Grails 2.4.3 and Hibernate 4 Compatibility Fix

Made some minor plugin setting tweaks so that it can work with the latest Grails version (2.4.3) and Hibernate 4. 

All tweaks are in commit [2a5cc51](https://github.com/appcela/grails-hibernate-filter/commit/2a5cc512732076053bf0be255a85f52bfb1cba33). Rest of the commits are for README.md changes, which can be ignored.

Thanks