Rename FFMPEG_SDK -> FFMPEG_HOME as it is said in wiki

Fix #942

CI/before_script.msvc.sh

@@ -405,7 +405,7 @@ printf "FFmpeg 2.5.2... "
 		rm -rf ffmpeg-2.5.2-win$BITS-dev
 	fi
 
-	export FFMPEG_SDK="`real_pwd`/FFmpeg"
+	export FFMPEG_HOME="`real_pwd`/FFmpeg"
 	add_runtime_dlls `pwd`/FFmpeg/bin/{avcodec-56,avformat-56,avutil-54,swresample-1,swscale-3}.dll
 
 	if [ $BITS -eq 32 ]; then

cmake/FindFFmpeg.cmake

@@ -2,7 +2,7 @@
 # - Try to find the required ffmpeg components
 #
 # This module accepts the following env variable
-#  FFMPEG_SDK - Can be set to custom install path
+#  FFMPEG_HOME - Can be set to custom install path
 #
 # Once done this will define
 #  FFmpeg_FOUND         - System has the all required components.
@@ -42,10 +42,11 @@ macro(_internal_find_component _component _pkgconfig _library _header)
     set(_package_component FFmpeg_${_component})
     libfind_pkg_detect(${_package_component} ${_pkgconfig}
         FIND_PATH ${_header}
-            HINTS $ENV{FFMPEG_SDK}/include
-            PATH_SUFFIXES ffmpeg
+            HINTS $ENV{FFMPEG_HOME}
+            PATH_SUFFIXES include ffmpeg
         FIND_LIBRARY ${_library}
-            HINTS $ENV{FFMPEG_SDK}/lib
+            HINTS $ENV{FFMPEG_HOME}
+            PATH_SUFFIXES lib
     )
     set(${_package_component}_DEFINITIONS  ${${_package_component}_PKGCONF_CFLAGS_OTHER})
     set(${_package_component}_VERSION      ${${_package_component}_PKGCONF_VERSION})

cmake/FindFreetype.cmake

@@ -10,7 +10,7 @@
 # - Try to find FreeType
 #
 # This module accepts the following env variable
-#  FREETYPE_SDK - Can be set to custom install path
+#  FREETYPE_DIR - Can be set to custom install path
 #
 # Once done, this will define
 #
@@ -62,11 +62,11 @@ set(_REGULAR_INSTALL_PATHS
 
 libfind_pkg_detect(Freetype freetype2
     FIND_PATH ft2build.h
-        HINTS $ENV{FREETYPE_SDK}
+        HINTS $ENV{FREETYPE_DIR}
         PATHS ${_REGULAR_INSTALL_PATHS}
         PATH_SUFFIXES include freetype2
     FIND_LIBRARY freetype freetype2311 freetype239 freetype238 freetype235 freetype219
-        HINTS $ENV{FREETYPE_SDK}
+        HINTS $ENV{FREETYPE_DIR}
         PATHS ${_REGULAR_INSTALL_PATHS}
         PATH_SUFFIXES lib
 )