Fixes the menubar not resizing with the Window
Fixes the Editors Menubar item not being repopulated if the editor was closed/reopened
Fixes the Physics menubar item not appearing if the editor was closed/reopened
Fixes issue where findMenu could fail if the StringTableEntry happened to trip against a different capitalization.
This makes some tweaks to the engine to support this, specifically, it tweaks the hardcoded shaderpaths to defer to a pref variable, so none of the shader paths are hardcoded.
Also tweaks how post effects read in texture files, removing a bizzare filepath interpretation choice, where if the file path didn't start with "/" it forcefully appended the script's file path. This made it impossible to have images not in the same dir as the script file defining the post effect.
This was changed and the existing template's post effects tweaked for now to just add "./" to those few paths impacted, as well as the perf vars to support the non-hardcoded shader paths in the engine.
