Install a symlink to giddyup from a PATH'd location
Factor out the common code into reusable functions

The rationale here is to make it easy-to-trivial to write different
deployment scripts that all use the same basic logic around hooks, shared
files, and release directories/symlinking, and only change the few lines of
code that actually need to deal with populating a release directory.
Symlinking with force
Crazy backwards ln args