KORE tests and improvements

 - changed the underlying representation of KList to a linked list
 - made most other KORE classes be treatable as a KList (at least from Scala)
 - changed the signature of the Transformers to match Java 8 lambdas
 - added many tests
small fixes

Conflicts:
	kernel/src/test/java/org/kframework/kore/TestKILtoKORE.java
Merge pull request #1162 from cos/feature/inner-kore-improvements

Feature/inner kore improvements