[IMP-dev] 2.1 release branch created

I created the 2.1 release branch (release/2.1). It would be nice if anyone who hasn't updated in a while checks it out and makes sure there stuff works with it. To check it out do `git imp update` `git checkout -b release/2.1 origin/release/2.1` then build.

An issue I just discovered is that the version number support got broken along the way, so you version number will be wrong. I'll fix that shortly.