Remove cruft from user profile threads

This removes the vote button from threads on the user profile, which was
the only interaction available on the page other than the link to view
the thread in the main discussion view.
Add pagination to forum user profile page
Set initial video quality to large instead of default to avoid automatic switch to HD when iframe resizes. [BLD 981]
Separate each problem type into its own file

Separate all exercise and tool types, and create a new folder to contain them.
Merge pull request #3360 from edx/DOC-224

Doc 224
Merge pull request #3447 from edx/jmclaus/bugfix_hd_button_activates_by_itself

Set initial video quality to large instead of default to avoid automatic switch to HD when iframe resizes. [BLD 981]
Typo corrections
Merge pull request #3453 from edx/sylvia/docs/DOC-224

Typo corrections
DOC-115 adds topics to make data interpretation easier
Merge pull request #3287 from edx/ahodges/documentation/DOC115

Ahodges/documentation/doc115
Removed trailing periods in two scenario names
Merge pull request #3456 from edx/clytwynec/remove-trailing-periods-in-scenario-names

Remove trailing periods in scenario names
Merge pull request #3391 from edx/gprice/user-profile-pagination

Add pagination to forum user profile
add acceptance tests for user profile pagination.

JIRA: FOR-492
Re-add mutiple choice advanced options
Merge pull request #3459 from edx/sylvia/docs/multiple_choice

Re-add mutiple choice advanced options
Make TinyMCE more tolerant about HTML elements

STUD-1565
fixes templating error (LMS-2560)
Remove verify_html as it isn't supported in TinyMCE 4
Add support for raw HTML editor.

STUD-1562