Added a new script for checking postgres 9.2

PostgreSQL 9.2 introduced some changes to the pg_stat_activity table
that aren't backwards compatible. Addressing those changes here.
Changing permissions for execute
Fixed placement of wildcard and added info to top of file
Updated README to reflect new postgres 9.2 script
Merge pull request #3 from mikeokner/master

Added support for PostgreSQL 9.2