Automate builds using tup

This is what I've been using so far. [Tup](http://gittup.org/tup/) is a nice build automation tool that has a pretty concise syntax and does some fancy DAG and file system analysis to figure out whether somethings needs rebuilding. Neat for now but it could use a couple more features sometimes. I'm unsure whether it might make sense to use a more complex system like SCons or cmake in the end.