Feature/datasource connection pooling support

Current datasource config doesn't use connection pooling 
which will be a performance issue in long run

Added connection pooling support with c3p0 ComboPooledDataSource

Ref:
http://javatech.org/2007/11/c3p0-connectionpool-configuration-rules-of-thumb/
http://www.mchange.com/projects/c3p0/index.html