first draft of visitor refactoring

this commit breaks everything ever, I know. But I want to get reviews done on the interface for visitors before I start making changes to the entire code base to support the new API.

Note that while I'm sure I'll have to do some fine-tuning, this is designed to serve as a drop-in replacement for what already existed, except that BasicHookWorker has now become
LocalTransformer in keeping with its similarity in function to LocalTransformer in org.kframework.backend.java
add generic throws parameter, plus remove type parameters from drop-in replacement visitors
remove more type parameters to make this easier to replace legacy code
first draft of code to make everything compile
fix the remaining compiler errors, plus do some cleanup and fix bugs
Merge branch 'master' into visitor

Conflicts:
	src/javasources/KTool/src/org/kframework/backend/symbolic/AddPCToBagVariable.java
	src/javasources/KTool/src/org/kframework/backend/symbolic/ResolveLtlAttributes.java
	src/javasources/KTool/src/org/kframework/kil/KList.java
	src/javasources/KTool/src/org/kframework/kil/UserList.java
	src/javasources/KTool/src/org/kframework/kil/visitors/BasicTransformer.java
add copyright
fix some inconsistencies in AbstractVisitor
fix DataStructureBuiltin problems with MaudeFilter
Merge branch 'master' into visitor

Conflicts:
	src/javasources/KTool/src/org/kframework/kil/TermCons.java
fix bug with recomputeSort not being called when constructing rewrites
Merge branch 'master' into visitor

Conflicts:
	src/javasources/KTool/src/org/kframework/backend/java/kil/JavaSymbolicObject.java
	src/javasources/KTool/src/org/kframework/kil/TermCons.java
	src/javasources/KTool/src/org/kframework/kil/visitors/BasicTransformer.java
	src/javasources/KTool/src/org/kframework/kil/visitors/CopyOnWriteTransformer.java
fix copyright casing
fix copyright on one more file
fix tutorial files after solving pretty printing bug
fix one last file in tutorial
address code review comments
add complete method to ensure cache consistency
fix bug with caching visitors

Apparently if we actually cache BasicVisitor like we were supposed
to be doing in all cases regardless of whether the visit method
is overridden, it breaks the unparser. Not surprising, but it still
needs to be fixed. Hence, NonCachingVisitor.
fix copyright