Fixing performance-faster-string-find issues

This addresses the Clang Tidy check [performance-faster-string-find](https://clang.llvm.org/extra/clang-tidy/checks/performance-faster-string-find.html).

apps/mwiniimporter/importer.cpp

@@ -686,12 +686,12 @@ MwIniImporter::multistrmap MwIniImporter::loadIniFile(const boost::filesystem::p
             continue;
         }
 
-        int comment_pos = line.find(";");
+        int comment_pos = line.find(';');
         if(comment_pos > 0) {
             line = line.substr(0,comment_pos);
         }
 
-        int pos = line.find("=");
+        int pos = line.find('=');
         if(pos < 1) {
             continue;
         }
@@ -722,7 +722,7 @@ MwIniImporter::multistrmap MwIniImporter::loadCfgFile(const boost::filesystem::p
     while (std::getline(file, line)) {
 
         // we cant say comment by only looking at first char anymore
-        int comment_pos = line.find("#");
+        int comment_pos = line.find('#');
         if(comment_pos > 0) {
             line = line.substr(0,comment_pos);
         }
@@ -731,7 +731,7 @@ MwIniImporter::multistrmap MwIniImporter::loadCfgFile(const boost::filesystem::p
             continue;
         }
 
-        int pos = line.find("=");
+        int pos = line.find('=');
         if(pos < 1) {
             continue;
         }

apps/niftest/niftest.cpp

@@ -20,7 +20,7 @@ namespace bfs = boost::filesystem;
 ///See if the file has the named extension
 bool hasExtension(std::string filename, std::string  extensionToFind)
 {
-    std::string extension = filename.substr(filename.find_last_of(".")+1);
+    std::string extension = filename.substr(filename.find_last_of('.')+1);
 
     //Convert strings to lower case for comparison
     std::transform(extension.begin(), extension.end(), extension.begin(), ::tolower);

apps/opencs/model/prefs/shortcutmanager.cpp

@@ -178,7 +178,7 @@ namespace CSMPrefs
     {
         const int MaxKeys = 4; // A limitation of QKeySequence
 
-        size_t end = data.find(";");
+        size_t end = data.find(';');
         size_t size = std::min(end, data.size());
 
         std::string value = data.substr(0, size);
@@ -191,7 +191,7 @@ namespace CSMPrefs
 
         while (start < value.size())
         {
-            end = data.find("+", start);
+            end = data.find('+', start);
             end = std::min(end, value.size());
 
             std::string name = value.substr(start, end - start);
@@ -243,7 +243,7 @@ namespace CSMPrefs
 
     void ShortcutManager::convertFromString(const std::string& data, int& modifier) const
     {
-        size_t start = data.find(";") + 1;
+        size_t start = data.find(';') + 1;
         start = std::min(start, data.size());
 
         std::string name = data.substr(start);

apps/opencs/view/render/terraintexturemode.cpp

@@ -332,7 +332,7 @@ void CSVRender::TerrainTextureMode::editTerrainTextureGrid(const WorldspaceHitRe
 
     int textureColumn = landTable.findColumnIndex(CSMWorld::Columns::ColumnId_LandTexturesIndex);
 
-    std::size_t hashlocation = mBrushTexture.find("#");
+    std::size_t hashlocation = mBrushTexture.find('#');
     std::string mBrushTextureInt = mBrushTexture.substr (hashlocation+1);
     int brushInt = stoi(mBrushTexture.substr (hashlocation+1))+1; // All indices are offset by +1
 

apps/openmw/mwgui/tooltips.cpp

@@ -266,7 +266,7 @@ namespace MWGui
                     std::map<std::string, std::string> userStrings = focus->getUserStrings();
                     for (auto& userStringPair : userStrings)
                     {
-                        size_t underscorePos = userStringPair.first.find("_");
+                        size_t underscorePos = userStringPair.first.find('_');
                         if (underscorePos == std::string::npos)
                             continue;
                         std::string key = userStringPair.first.substr(0, underscorePos);

components/debug/gldebug.cpp

@@ -179,7 +179,7 @@ namespace Debug
         if (str.length() == 0)
             return true;
 
-        return str.find("OFF") == std::string::npos && str.find("0") == std::string::npos && str.find("NO") == std::string::npos;
+        return str.find("OFF") == std::string::npos && str.find('0') == std::string::npos && str.find("NO") == std::string::npos;
     }
 
     DebugGroup::DebugGroup(const std::string & message, GLuint id)

components/fallback/validate.cpp

@@ -12,7 +12,7 @@ void Fallback::validate(boost::any& v, std::vector<std::string> const& tokens, F
     for (const auto& token : tokens)
     {
         std::string temp = Files::EscapeHashString::processString(token);
-        size_t sep = temp.find(",");
+        size_t sep = temp.find(',');
         if (sep < 1 || sep == temp.length() - 1 || sep == std::string::npos)
             throw boost::program_options::validation_error(boost::program_options::validation_error::invalid_option_value);
 

components/resource/scenemanager.cpp

@@ -500,7 +500,7 @@ namespace Resource
         {
             std::string str(env);
 
-            if(str.find("OFF")!=std::string::npos || str.find("0")!= std::string::npos) options = 0;
+            if(str.find("OFF")!=std::string::npos || str.find('0')!= std::string::npos) options = 0;
 
             if(str.find("~FLATTEN_STATIC_TRANSFORMS")!=std::string::npos) options ^= Optimizer::FLATTEN_STATIC_TRANSFORMS;
             else if(str.find("FLATTEN_STATIC_TRANSFORMS")!=std::string::npos) options |= Optimizer::FLATTEN_STATIC_TRANSFORMS;

components/widgets/imagebutton.cpp

@@ -118,7 +118,7 @@ namespace Gui
 
     void ImageButton::setImage(const std::string &image)
     {
-        size_t extpos = image.find_last_of(".");
+        size_t extpos = image.find_last_of('.');
         std::string imageNoExt = image.substr(0, extpos);
 
         std::string ext = image.substr(extpos);