Add refresh streams to results barplot
Fix SQL typo in pgsql data loading
Explicitly name indexes

Postgres's automatic index naming doesn't avoid collisions.
Remove configuration of postgres binaries

In hindsight, it is easier to install the scripts once and change the
PATH environment to test different installations of postgres.
Fix pgsql refresh scripts

- Simplified and parallelized the refresh stream tasks.
- Generate refresh data outside of the timing of the test execution.
- Removed use of procmails lockfile.
- Generate the number of refresh stream sets according to the streams
  set as opposed to a fixed 12 sets.
Run pgsql refresh stream concurrently with queries
Fix dataset generation

Create datasets for the refresh streams before starting the tests.
Create the throughput datasets in addition to the powertest dataset
otherwise there will be primary key collisions in the inserts.