remove all references to maude backend and make java the default
fixes for java backend productions that represent klabel constants
fix agent to work in java backend
fix regression tests to work in java backend
add documentation for OfKItem methods
Merge branch 'master' into kill-maude-dead2

Conflicts:
	maude-backend/pom.xml
Merge pull request #1255 from dwightguth/kill-maude-dead2

remove maude backend and make java the default