Enable clang
Add debug and fix PROTOTYPE.replace_slot
Updated ruby tests
Make dispatch/bool.feature @future and add dispatch/dispatch.feature
Move tests around (cucumber support for subdirectories not as expected)
Added "E:" prefix to error message (more robust in tests)
Fix dispatch-dispatch.feature and parse keywords before types
WIP dispatching, refactor ITM_EXPR hierarchy, implemented Expanded

trying to get the dispatching working, and did some refactoring in
the process:

* Implemented Expanded keyword in type declaration (not just in
  the Section Header). Changes in a few locations that went with
  the default specified in Section Header

* ITM_EXPR.compile_in get a TYPES argument that is a hist to what
  it should compile to. This is useful in some circumstances
  (ITM_EXPR_PROTO for example)

* `parent_root :Expanded ROOT` does no longer raise an error at
  compile time