Fix windows builds

Can't instantiate a container (at least with MSVC) without knowing the exact size of the object being stored, forward-declares only work with pointers.
I couldn't see a simple way to remove the forward declare, so pointers and memory management it is.

apps/openmw/mwsound/soundmanagerimp.cpp

@@ -104,9 +104,10 @@ namespace MWSound
             SoundBufferList::iterator sfxiter = mSoundBuffers.begin();
             for(;sfxiter != mSoundBuffers.end();++sfxiter)
             {
-                if(sfxiter->mHandle)
-                    mOutput->unloadSound(sfxiter->mHandle);
-                sfxiter->mHandle = 0;
+                if((*sfxiter)->mHandle)
+                    mOutput->unloadSound((*sfxiter)->mHandle);
+                (*sfxiter)->mHandle = 0;
+                delete (*sfxiter);
             }
             mUnusedBuffers.clear();
         }
@@ -145,8 +146,8 @@ namespace MWSound
         min = std::max(min, 1.0f);
         max = std::max(min, max);
 
-        Sound_Buffer *sfx = &*mSoundBuffers.insert(mSoundBuffers.end(),
-            Sound_Buffer("Sound/"+sound->mSound, volume, min, max)
+        Sound_Buffer *sfx = *mSoundBuffers.insert(mSoundBuffers.end(),
+            new Sound_Buffer("Sound/"+sound->mSound, volume, min, max)
         );
         mVFS->normalizeFilename(sfx->mResourceName);
 

apps/openmw/mwsound/soundmanagerimp.hpp

@@ -56,7 +56,7 @@ namespace MWSound
         float mVoiceVolume;
         float mFootstepsVolume;
 
-        typedef std::deque<Sound_Buffer> SoundBufferList;
+        typedef std::deque<Sound_Buffer*> SoundBufferList;
         // List of sound buffers, grown as needed. New enties are added to the
         // back, allowing existing Sound_Buffer references/pointers to remain
         // valid.