* adds support for `--psol-from-source` so you don't need binary modules, and `--devel` so you can run our tests without going and getting all our dependencies
* adds submodules for testing: mod_pagespeed, ngx_cache_purge etc
* adds support for running as:
```
git clone git@github.com:pagespeed/ngx_pagespeed.git
cd ngx_pagespeed/
git checkout <branch>
scripts/build_ngx_pagespeed.sh [options]
```
* depends on the scripts @hillsp is working on so that we can just check out mod_pagespeed and ask it to build and rebuild itself
* adds colors to output to make it easier to read
Jeff Kaufman
247a821564