Fix TAP output to show errors

TAP output was only showing success and failure results, but not errors.
So update TAP output to show errors as "not ok", just like failures.
Fix issue #272 Syntactic sugar does not work

Allow the following alternate syntax for context blocks:
  describe "something" (function()
    it "works" (function()
      assert(true)
    end)
  end)
Fix help string for the default seed value
Add shuffle commandline flag (alias for randomize)
Add commandline option to repeat tests
Update getTrace() to look for current file name
Support for running tests standalone

Allows unit tests to be run standalone by just adding a require to the
top of a test file. This is useful if, for some reason, a command line
tool is not viable.

Just add the following require statement to a test:

	require 'busted.runner'()

This addresses issue #294.
Fix indent in runner
Refactor runner to be compatible with live coding