chore(ng-bind-html): fix snakecase in map

Though both are accepted, the docs suggest using the snakecase version.
chore(node_cursor): remove unused variable
fix(directives): fixed error handling in directives registry
test(directive): Added a test for DirectiveRegistry
fix(parser_generator): fixed class selector
fix(ng_repeat): Gracefully handle non-lists
test(ng_repeat): Test for gracefully handling nulls