2.1.4 - important fix + improvements

This version fixes the various issues that snuck into a number of save/open .chr file actions; resolving a crash and further mishaps. 

It also makes working with the navigator & metatile editor an overall smoother experience; with less redundant cpu load at inconvenient times. 

Lastly, another hotkey was added. While on the nametable/map, N toggles the metatile editors' "clonestamp on" button. 
If you're new to it; the clonestamp temporarily replaces the regular tile brush as long as the metatile editor is open, and the "clonestamp on" button in that editor is down.