Jeck - Quad locking restored, minor cache fiddling.

* Restored quad locking to textures, but ignore quad locks when Release(JTexture*) is explicitly called. (I just copied and modified the code from the template, rather than do anything elegant). 
* Some minor fiddling with cache error states.

projects/mtg/src/WCachedResource.cpp

@@ -84,6 +84,18 @@ WCachedTexture::~WCachedTexture(){
 JTexture * WCachedTexture::Actual(){
   return texture;
 }
+bool WCachedTexture::isLocked(){
+  if(locks != WRES_UNLOCKED)
+    return true;
+
+  for(vector<WTrackedQuad*>::iterator it=trackedQuads.begin();it!=trackedQuads.end();it++){
+    if((*it)->isLocked())
+      return true;
+  }
+
+  return false;
+}
+
 bool WCachedTexture::ReleaseQuad(JQuad* quad){
   if(quad == NULL)
     return false;