fix(directive) unknown chart types are passed to Chart.js as-is

This fix allows ts-chartjs directive to be used with types other than those listed in the switch statement. This is useful when Chart.js has been extended with custom chart types. Also improved and added tests to cover the different cases.
docs(ts-chartjs) add documentation on passing unlisted values to chart-type
Merge branch 'master' into typePassThrough

Conflicts:
	Gruntfile.js
	bower.json
	dist/tc-angular-chartjs.js
	dist/tc-angular-chartjs.min.js
	package.json
	src/tc-angular-chartjs.js
	test/unit/tc-angular-chartjs.spec.js
fix(build) add ignores to test/.jshint, create new build
Merge pull request #4 from bostrom/typePassThrough

Passing unlisted chart types as-is to Chart.js