add connection pool to mysql configuration
Switch to IBM JRE 7.1 and Liberty 8.5.5.3
connection pool size may be specified in configuration
Merge pull request #120 from pradine/master

Switch to IBM JRE 7.1 and Liberty 8.5.5.3
Merge pull request #121 from stopyro/RTC142903

Optionally configure connection pool for mysql / postgresql.