Postgres.app 2041425 fix

Instructions reference Postgres.app as the quickest/easiest way to get Postgres on Mac, but when you run ./dev, you get this error:

java.lang.Exception: Could not find Postgres 9.0-9.3. Please install initdb, postgres (which must be executable) in one of: /usr/bin, /bin, /usr/sbin, /sbin, /usr/local/bin, /usr/sbin, /usr/local/sbin, /usr/lib/postgresql/9.3/bin, /usr/lib/postgresql/9.2/bin, /usr/lib/postgresql/9.1/bin, /usr/lib/postgresql/9.0/bin, /usr/bin, /usr/local/bin, /usr/local/pgsql/bin, /opt/local/lib, /opt/local/lib/postgresql93/bin, /opt/local/lib/postgresql92/bin, /opt/local/lib/postgresql91/bin, /opt/local/lib/postgresql90/bin, /Applications/Postgres.app/Contents/MacOS/bin, /Applications/Postgres93.app/Contents/MacOS/bin, /sw/opt/postgresql-9.3/bin, /sw/opt/postgresql-9.2/bin, /sw/opt/postgresql-9.1/bin, /sw/opt/postgresql-9.0/bin, /opt/PostgreSQL/9.3/bin, /opt/PostgreSQL/9.2/bin, /opt/PostgreSQL/9.1/bin, /opt/PostgreSQL/9.0/bin, /Library/PostgreSQL/9.3/bin, /Library/PostgreSQL/9.2/bin, /Library/PostgreSQL/9.1/bin, /Library/PostgreSQL/9.0/bin

Looks like latest version of Postgres.app has the postgres/initdb/etc bins in a different dir than before. Added dir to PostgresCommand.scala and now Overview runs when I run ./dev