gulp-concat-sourcemap should support the gulp-sourcmap standard, and be able to receive sourcemaps on the file object and emit sourcemaps on the file object
Merge branch 'issue-8' of https://github.com/mariusGundersen/gulp-concat-sourcemap into mariusGundersen-issue-8

Conflicts:
	test/test.js
Merge branch 'mariusGundersen-issue-8'