Revert "Returned files that impact gameplay to their original condition"

This reverts commit 24590d871ddb2637d8b187168630dd89f9fb7c6e.
Merge pull request #2 from vaendryl/master

Resync to vaendryl
Merge remote-tracking branch 'origin/ModdingImprovements'
Merge remote-tracking branch 'origin/master'
Coded changes to AI so that it will consider closing in on the enemy, if it can do more damage that way.  Also a little tidying.  Couldn't test because the battle_dispatcher doesn't seem to be instantiated.
AI for 'move then shoot' decision in battle.  Limited testing now completed.
Safe version of all files
Working version of 'AI considers advancing'
Working version of 'AI considers advancing'.  Also fixed some odd syntax problems in screens custom.rpy that were preventing me from executing, and removed the try...except stuff from the dispatcher because it was making it impossible to debug my AI code when it threw exceptions.