[Truffle] - Implementing Class#superclass method.
[Truffle] - Allows using self as the superclass if self is a class.
[Truffle] - Added method getRubySuperClass method to DefineOrGetClassNode.

DefineOrGetClassNode: moving code that gets the superclass (or raise a
typeError) to a new method: getRubySuperClass().
[Truffle] - Showing Ruby stacktrace when running code outside of a
class/module context.
[Truffle] - A class definition raises a TypeError if inheriting from a metaclass.
[IR] Added error-catching assertions in interpreter loop

* Found a few problems with IR operands/instructions because of
  this. Will be fixed in later patches.
[IR] NonLocalReturns can raise LocalJumpError
[Truffle] New dispatch mechanism.
[Truffle] Missing copyright.
Merge branch master into truffle-head.
[Truffle] implemented Object#<=>, Object#eql? Module#<= and Module#<=>
[Truffle] Merge.
[Truffle] Cleaned up accident in previous merge.
Actually implement RubyNumeric.getIntValue and document behavior.
Merge JI #raise and Kernel#raise since JI is always on now.
Make err logging of bubbled exceptions a bit more robust.
Eliminate unnecessary cast exception for every Java class on load.
Grr...I always reverse this relationship.
Update to new jnr-posix snapshot
Short-circuit jar resources if they do not start with first letter of their supported schemes -- improves startup time