FileSystem: Make path caching optional via config

Because Windows has case insensitive paths, this should
be turned on (which it is by default) for maximum
compatibility. Can be turned off as an optimization
(this will speed up startup a little depending on the
number of game assets).

src/config.cpp

@@ -45,26 +45,28 @@ Config::Config()
       frameSkip(true),
       solidFonts(false),
       gameFolder("."),
-      allowSymlinks(false)
+      allowSymlinks(false),
+      pathCache(true)
 {}
 
 void Config::read()
 {
 #define PO_DESC_ALL \
 	PO_DESC(debugMode, bool) \
-    PO_DESC(winResizable, bool) \
-    PO_DESC(fullscreen, bool) \
-    PO_DESC(fixedAspectRatio, bool) \
-    PO_DESC(smoothScaling, bool) \
-    PO_DESC(vsync, bool) \
-    PO_DESC(defScreenW, int) \
-    PO_DESC(defScreenH, int) \
-    PO_DESC(fixedFramerate, int) \
-    PO_DESC(frameSkip, bool) \
-    PO_DESC(solidFonts, bool) \
-    PO_DESC(gameFolder, std::string) \
-    PO_DESC(allowSymlinks, bool) \
-    PO_DESC(customScript, std::string)
+	PO_DESC(winResizable, bool) \
+	PO_DESC(fullscreen, bool) \
+	PO_DESC(fixedAspectRatio, bool) \
+	PO_DESC(smoothScaling, bool) \
+	PO_DESC(vsync, bool) \
+	PO_DESC(defScreenW, int) \
+	PO_DESC(defScreenH, int) \
+	PO_DESC(fixedFramerate, int) \
+	PO_DESC(frameSkip, bool) \
+	PO_DESC(solidFonts, bool) \
+	PO_DESC(gameFolder, std::string) \
+	PO_DESC(allowSymlinks, bool) \
+	PO_DESC(customScript, std::string) \
+	PO_DESC(pathCache, bool)
 
 #define PO_DESC(key, type) (#key, po::value< type >()->default_value(key))