WIP: Make curl thread code robust and flexible.

Conflicts:

	indra/llmessage/llcurl.cpp
	indra/llmessage/llcurl.h
	indra/newview/app_settings/settings.xml
	indra/newview/llappviewer.cpp
	indra/newview/llmeshrepository.cpp

Resolved:

	indra/llmessage/llcurl.cpp:

	  Basically removed (not used anyway)

	indra/llmessage/llcurl.h:

	  Basically removed (just includes aiculr.h now)

	indra/newview/app_settings/settings.xml:

	  CurlUseMultipleThreads was remvoved.
	  CurlMaximumNumberOfHandles and CurlRequestTimeOut
	  are still in there, but unused at the moment.

	indra/newview/llappviewer.cpp:

	  CurlMaximumNumberOfHandles and CurlRequestTimeOut
	  are unused at the moment.

	indra/newview/llmeshrepository.cpp:

	  Lock mSignal always (is unlocked inside wait()).
	  Use mSignal lock to see if we are waiting; remove mWaiting.
	  Return false from the MeshFetch functions iff we have to retry
	  a HTTP fetch. Catch the error exception thrown by getByteRange
	  instead of using it's return value (always returns true
	  anyway).

indra/newview/lltexturefetch.h

@@ -37,7 +37,7 @@
 #include "llimage.h"
 #include "lluuid.h"
 #include "llworkerthread.h"
-#include "llcurl.h"
+#include "llcurlrequest.h"
 #include "lltextureinfo.h"
 #include "llapr.h"
 
@@ -107,7 +107,7 @@ public:
 							LLViewerAssetStats * main_stats);
 	void commandDataBreak();
 
-	LLCurlRequest & getCurlRequest()	{ return *mCurlGetRequest; }
+	AICurlInterface::Request& getCurlRequest()	{ return *mCurlGetRequest; }
 
 	bool isQAMode() const				{ return mQAMode; }
 
@@ -178,7 +178,7 @@ private:
 
 	LLTextureCache* mTextureCache;
 	LLImageDecodeThread* mImageDecodeThread;
-	LLCurlRequest* mCurlGetRequest;
+	AICurlInterface::Request* mCurlGetRequest;
 	
 	// Map of all requests by UUID
 	typedef std::map<LLUUID,LLTextureFetchWorker*> map_t;