SNOW-764 (problem 1) FIXED Bugs showing when compiling with optimization

also fixes:
SNOW-522 FIXED crash due to looking for skins/paths.xml at the wrong path

originally commited at http://svn.secondlife.com/trac/linden/changeset/3550

SVN changeset did not apply automatically due to changed context.
Manually applied changes, which was straight forward.

Added SNOW-522 in doc/contributions.txt, because that's fixed by this, too.
(transplanted from 8afc8382dd9bddd4968060d306d96218d571a171)

doc/contributions.txt

@@ -61,6 +61,8 @@ Aimee Trescothick
 Alejandro Rosenthal
 	VWR-1184
 Aleric Inglewood
+	SNOW-522
+	SNOW-764
 	VWR-10001
 	VWR-10759
 	VWR-10837

indra/llvfs/lldir_linux.cpp

@@ -93,7 +93,7 @@ LLDir_Linux::LLDir_Linux()
 #else
 	mAppRODataDir = tmp_str;
 #endif
-    U32 indra_pos = mExecutableDir.find("/indra");
+    std::string::size_type indra_pos = mExecutableDir.find("/indra");
     if (indra_pos != std::string::npos)
     {
 		// ...we're in a dev checkout