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/llioutil.cpp

@@ -27,7 +27,6 @@
  */
 
 #include "linden_common.h"
-#include "llfasttimer.h"
 #include "llioutil.h"
 
 /**