remove use of deprecated DGM sort method
Change type handling to work with Groovy 2.3 and JDK8
fix types to be compatible with Groovy 2.3 + JDK8
don't use deprecated DGM count method

This is more compatible with Groovy 2.3 and JDK8
add generic type information

Groovy 2.3 and JDK8 still are not going to allow this to compile.  More investigation pending.
remove @Override

See https://jira.codehaus.org/browse/GROOVY-5413
See https://jira.codehaus.org/browse/GROOVY-6465

Conflicts:
	grails-bootstrap/src/main/groovy/org/codehaus/groovy/grails/plugins/GrailsVersionUtils.groovy
address duplicate method declaration issue
Merge branch 'master' into groovy_2.3_jdk8