Drop use of tempfiles when loading compressed files.

Also simplified .zga texture and .aqs savegame loading.
Dropped support for "crunched" .sav files (those were never used),
and the corresponding crunch functions.

To be done: Temp files are still used when compressing files,
will address this in a later commit.

ExternalLibs/tinyxml.cpp

@@ -993,6 +993,11 @@ bool TiXmlDocument::LoadFile( FILE* file, TiXmlEncoding encoding )
 		return false;
 	}
 
+	return LoadMem(buf, length, encoding);
+}
+
+bool TiXmlDocument::LoadMem( char* buf, long length, TiXmlEncoding encoding )
+{
 	// Process the buffer in place to normalize new lines. (See comment above.)
 	// Copies from the 'p' to 'q' pointer, where p can advance faster if
 	// a newline-carriage return is hit.