Further header cleanup and a few updates

Updated llstring to current linden
Further linden_common cleanup
Header cleanup
Raised banlines to 5000 as per linden server change
Included missing llmediaentry.cpp file
Minor whitespace changes here and there

indra/llmessage/lliosocket.cpp

@@ -32,7 +32,6 @@
 #include "llapr.h"
 
 #include "llbuffer.h"
-#include "llfasttimer.h"
 #include "llhost.h"
 #include "llmemtype.h"
 #include "llpumpio.h"