add 'grunt test' task to compile and run tests
remove test_runner.js if tests run without error
'npm test' now executes 'grunt test'
Merge pull request #983 from mkroehnert/testing

Use Grunt and plugins to do all the testing instead of shell scripting
cli: Important detail for -d to work re-added.

It must have been lost during some files moves etc.
amberc: exit when --help is specified (fix #964)
Grunt: shorten task names