Merge pull request #396 from bobbywarner/plugins

Hibernate Plugin update in app.pom and assemble.gradle
update LICENSE and README
version 2.3.1.BUILD-SNAPSHOT
version 2.4.0.BUILD-SNAPSHOT
Possible solution for GRAILS-10454 - changed the way of getting real class of hibernate proxied object
GRAILS-10397 - improve how the data binder identifies domain classes
Merge branch '2.3.x'
Update Groovy to 2.1.7
Use localeResolver in LocaleAwareNumberConverter
Merge branch '2.3.x'
GRAILS-10448 - use spring 4.0.0.BUILD-SNAPSHOT
GRAILS-10448 - temporarily use http://repo.springsource.org/libs-milestone repo
GRAILS-10448 - get a clean compile

All of these changes are temporary and need to be addressed individually.  This is just a step to get the code base compiling against Spring 4 so I can move forward with some specific relevant work.  The changes in this commit will be addressed later.
GRAILS-5779 - start removing bean builder code

Use the corresponding library provided by Spring 4
GRAILS-5779 - grails-core depends on spring-lang-groovy for bean builder
classes
GRAILS-10448 - introduce our own ExpressionEvaluationUtils for now
GRAILS-10448 - replace WebUtils.exposeForwardRequestAttributes which was removed from Spring 4
GRAILS-10448 - fix call to ClassUtils.forName
GRAILS-10448 - use our temporary ExpressionEvaluationUtils
GRAILS-10448 - imported the wrong Assert