Makefile doesn't need to be executable.
Rename test file to better reflect what it is testing.
Catch javascript exceptions in handler and rethrow from apply().

This way exception handling is done like the javascript developer would expect.
Make some functions and parameters const and/or use refs.
Cleanup of object unwrapping code.

Several different ways of unwrapping Javascript objects to get to the C++
objects were used, this is now cleaner.
Code cleanup.
Consolidate tags() functions.
Implement LocationHandler::clear() method.
Remove unused _ref and _unref methods on LocationHandler.
Fixed indentation.