chore($compile): make webstorm's regexp parser happy

Minor change puts \- at end of character pattern

In CLASS_DIRECTIVE_REGEXP and COMMENT_DIRECTIVE_REGEXP, putting the \- character at
the end of the character patter speeds up many IDE parsers and alleviates some
errors in certain IDE's. (WebStorm 8)

Functionally absolutely equivalent. No test change needed.

Closes #7093

Conflicts:
	src/ng/compile.js