Fix for  GRAILS-10520 :  Added logic for handling circular references for domain objects (when loaded eagerly).
Pending: Unit Tests.
Unit Test for GRAILS-10520 :  Added Unit Test for domain with eagerly loaded associations..
GRAILS-10799 Minor optimization to GrailsWebUtil.getContentType
GRAILS-9056 Unify content type setting in RenderDynamicMethod, fix rendering file
GRAILS-10799 Implement Writable for JSONObject and optimize it
GRAILS-10799 Implement streaming value writing to JSONWriter
GRAILS-10799 Optimize "render obj as JSON" performance
GRAILS-10799 Add stateless streaming encoder to optimize javascript value escaping
Test for GRAILS-9056
Merge pull request #428 from sukrit007/GRAILS-10520

Grails-10520
Merge branch '2.3.x'