Postgres Testing

I spent some time bringing up a Postgres version of CHORDS on my MacBook Pro. It's in the pg branch. There were a few MySQL/Postgres differences that required code changes.

The main point was to see if Postgres gave better performance than MySQL. There didn't seem to be any improvements at all. This was true before and after the dashboard_helper refactor.

I also experimented with changing some recommended Postgres database configuration parameters:

• Changed shared_buffers to 1024MB
• Changed work_mem to 1024B
• Enabled all of the query tuning options

None of these made any difference in the dashboard rendering time.