AHK v2 compatible

I've made this unit testing framework fully compatible with AHK v2 alpha, as well as kept it backwards compatible with AHK v1.1. I've kept each commit distinct, so you can easily see each change and the commit message has the reasoning behind it. 

The only potential issue is the removal of `#NoEnv`. There shouldn't be any issue with leaving that command out, but just in case, I haven't removed it entirely, but instead just commented it out.

Finally, if you also want to merge in the "add-icon" branch to use the Red X, you may end up with a merge conflict. You may want to merge this request first.