Check for exceptions when rendering studio and students views.

        Otherwise it's possible to reach stuck states.
leveraging some of the existing notification styling for component errors in studio
Added acceptance tests for get_html exception handling

Make tests conform to new import UI
additional copy and styling for component syntax error in studio
Review fixes
fixing alignment error on studio component error message, i18n error message
Review fixes
Review fixes
Merge pull request #1133 from edx/jkarni/fix/customtag-error

Jkarni/fix/customtag error