Port Viewer 2 indra/llvfs

This introduces some API changes, like the new LLDirIterator,
that causes changes elsewhere.

It also include Log Linden's cache changes that aren't in
viewer-development yet that increase the maximum cache size
to ~10 GB.

indra/llvfs/lllfsthread.cpp

@@ -227,7 +227,6 @@ bool LLLFSThread::Request::processRequest()
 		}
 		mBytesRead = outfile.write(mBuffer, mBytes );
 		complete = true;
-
 // 		llinfos << "LLLFSThread::WRITE:" << mFileName << " Bytes: " << mBytesRead << "/" << mBytes << " Offset:" << mOffset << llendl;
 	}
 	else