Capture metrics for problem attempts and histograms of problem grades
Make new-style chinese language codes works for translation

The old-style chinese language codes used in django 1.4 series are now deprecated, as discussed here:  https://code.djangoproject.com/ticket/18419.
Although majority of browsers still use the old-style language codes, some new browsers such as IE11 in Windows 8.1 start to use the new-style names instead of old-style ones which makes the current chinese translations of edX can't work properly under these browsers.
As there is no easy way for edX to change a higher version of django, I think we could do some mapping here so that the users who use IE11 in Windows 8.1 or other browsers that use the new-style names can view correct translations.
Also, this fix will make users who use one of the language codes:  zh-hk ,  zh-sg  and  zh-mo  can see the correct translations.
unicode fixes
line fix
Merge pull request #3162 from cpennington/problem-check-metrics

Capture metrics for problem attempts and histograms of problem grades
Merge pull request #3148 from louyihua/localization-fix

Make new-style chinese language codes works for translation
Instructor- and student-facing documentation for ORA2
Merge pull request #3044 from edx/sylviapearce/documentation/DOC-191

Sylviapearce/documentation/doc 191
Grading Documentation Update

DOC-97
DOC-176

Added note about grading subsections only, and vertical bars
representing subsections in progress tab
Temporarily disable studio acid block tests that are failing
Merge pull request #3174 from edx/zoldak/disable-acid

Temporarily disable studio acid block tests that are failing
Upgrade to TinyMCE 4.0.16.

Detailed commit messages:
deleted old tinymce

new tinymce
js changes to support new tinymce
scss changes for alignments

Include all the controls on the toolbar that we previously had.

Changes to support Bulk e-mail usage.

adding new studio skin for TinyMCE4

Get handling of static image links working again.

Delete old Studio skin.

Version 1.3 of CodeMirror plugin.

Modify paths for location of CodeMirror files.

Fire events when CodeMirror Editor is open and closed.

Needed to switch static links back and forth.

Remove CodeMirror tabbed editor.

fixed tinymce visual editor css

Change how we detect that an image has been inserted.

made the codemirror look more studio-like

reordered the tinymce buttons

Update unit tests.

Update acceptance test for image plugin.

Make sure to strip out temporary caret.

It can get left behind in style blocks.

Test for style block being maintained.

Allow TinyMCE to create p's, else formatting doesn't work.

Add tests for toolbar buttons and converting links.

Add test for code format toolbar button.

Remove unnecessary code.

Remove unused testing templates and unused tabs.

Update tinymce paths.

Fire an event with the link plugin closes so we can rewrite links.

pep8

Updates from code review.

Change the name of the button to "Edit HTML".

Changed menu name for consistency, but we don't show it.

Changed name of "code" toolbar button to "Code block".

Switch from tabbed Visual/HTML Editor for HTML modules to showing the code editor as a plugin within TinyMCE (triggered from toolbar). STUD-1422

Fire events before and after the image dialog is shown.

We use this to rewrite links.

Change the event handling for image plugin.

Fixes FireFox bug, and allows us to correct the image path when we show the plugin (as opposed ot only correcting path when we close the plugin).

Code review feedback.

Fire events before and after the link dialog is shown.

This allows us to convert the static links.

Remove unnecessary helper method.

keeping the component editor inside the component window

Use compressed CodeMirror file.

replaced code icon in TinyMCE editor; simplified UI on TMCE toolbar

Change code editor icon to say HTML.

Move code style block button.

Update tests for minor UI changes.

Code editor button no longer shows an icon, and code style toolbar button location has moved.

Fix typos.
Merge pull request #3171 from abdoosh00/unicode-fixes

unicode fixes
Don't hardcode https protocol in password reset email.

Use http or https, depending on the value of `is_secure`.
This is similar to how links in some other email templates work.
Merge pull request #3137 from edx/markhoeber/documentation/doc-97

Changes for doc-97 - Subsection grading
Use postMessage to communicate between the iframe and TinyMCE.

This gets around cross-origin issues on the CDN.

Delete plugin.min.js as the Jake command will minimize into the full file.
Tiny MCE version 4.0.20

Changed tiny-MCE to not load CSS files dynamically.
Added CSS files for tiny-MCE in env files.
Moved TinyMCE files to directory structure required by Jake command.
Changed clients of "tinymce.min.js" to use "tinymce.full.min.js" instead.
Updated CHANGELOG to indicate tinymce version 4.0.20.
Renamed tinymce.css.
Directions for creating tinymce.full.min.js and commenting of edX changes.
Updated comments related to disabling dynamic JS and CSS file loading in tinymce.
Allow TinyMCE to handle CSS within the iframe.
removing tinymce button border only on active to counteract fun LMS button styles
Add dialog plugin code to compressed JS file and CSS file.

Needed for TinyMCE CodeMirror plugin.
Directions for creating codemirror-compressed.js