Working mutation points

This is a solution to #159 

I have not limited when you can go into the editor, so you can easily get as many MP as you want by exiting and entering the editor, but I have added a dialog that lets you enter the editor after reproduction, so the only thing missing for restricted access is to restrict access from main menu and microbe stage menu dialog.

GUI changes for mutation points has been pushed to SVN. 

Loading a microbe resets your MP to 0 such that save&load will not be a way to exploit infinite MP when mutation becomes limited.