PostgreSQL 9.3.1

- Use sha256 instead of sha1, because the upstream download site
  provides the former.

- Remove various workarounds for PL/Python build issues.  These have all been fixed upstream.
postgresql::db no longer requires an Exec
Couple $datadir and $logdir to Postgres minor version
Forgot about tests :disappointed:
Merge pull request #26 from DanielWright/master

Bump to 9.3.1
Upgrade to 9.3.2
Kill stale pidfiles before starting the service

If you kill postgres badly, it leaves a `postmaster.pid` file lying
around which prevents the service from starting later. This gets in the
way of development, causes confusion, and *burns battery* as launchd
tries again and again to start postgres.

There are potential consequences to this in the case of a corrupt
database, but they're so unlikely that I much prefer to err on the side
of convenience for a developer machine.