Especially, the defaults in studio to use formulaequationinputs and some of
the documentation and examples.

Change some `is` comparison to `==`. Also, modify the `render_atom` method.

Holds the data for a particular parse (i.e. instantiated with a math
string and eventually holds a tree and sets of variables as well).

Test the `render_X` methods as well as `latex_preview` on the whole.
Add a few 'pragma: no cover's to hide unreachable code from coverage.

Start implementing some of Ned's comments.

This includes creating `render_X` methods for each branch. Create a class for
intermediate partially-done renderings.

YAY! It works! Mostly... and it needs tests.

Named `FormulaEquationInput` (name up for debate)
-For the initial pass, just copy off of ChemEqnIn
-Add FormulaEquationInput in inputtypes.py
-Add a call to a skeleton method for a preview

javascript:
-Queue up some MathJax
-Put some ordering on the AJAX requests: add a parameter when the request was started, when it returns check that it isn't outdated before displaying the preview

Double check that this does not introduce any errors. Also, get rid of old tests in xmodule (they are replicated in calc/tests/test_calc.py).

calc.py:
-Create a method called `parse_algebra`. It takes a string of math and returns with a `pyparsing.ParseResults` object representing it.
-`evaluator` takes this tree and applies the old "parse actions" to it to get the same number as it used to.
-Change a few things in the parse actions (i.e. rename them to eval actions)
-Add `atom_parse_action`
-Add `find_vars_funcs` to aggregate used functions and vars in the tree
-Change strategy of `check_variables` to instead take the set difference of `find_vars_funcs` with the allowed ones
-Create `add_defaults` to take user defined lists of vars and funcs and return a combined list
-Change `x.setResultsName(...)` to `x(...)` for brevity

In test_calc.py:
-Fix a bad test (which expected something to pass that shouldn't)
-Fix indentation

Update the XBlock version to fix save bugs

give some debug message regarding why export has failed

Valera/captions keyboard access 2

In speed control, when it is focused, a drop down becomes available which contains all
of the available speeds that the player can switch to. When using the Tab button to
tab through all of the controls, it should be possible to select individual speed with
the keyboard.

Only relevant part of string will go through the Python internationalization function.

Previously we were using dummy YouTube IDs such as "slowerSpeedYoutubeId", and "normalSpeedYoutubeId".
This was causing errors when the code tried to fetch metadata from YouTube with that ID. We can't
stub these fetch requests because the data that is fetched is necessary. For example it contains
the length of the video.

It turned out that we were reading the heights of the contols and other elements
before we initialized the heights.

Now all Video tags and VideoAlpha tags will be handled by VideoAlpha.

When the controls receive focus not via mouse click or mouse hover, their appropriate
slider and selection menu are fully extended and shown to the user.

Now when subs parameter is empty or the YouTube IDs are not specified,
captions will not try to fetch non-existent file.

It turns out that there was wrong invocation of toBeCloseTo() function. Most likely a typo.
Updated the readme.

Because sometimes the tooltips generated by qTip get in the way, and the controls becomes
not responsive, it was decided to use standard title attributes for tips.

Also along the way, an error was discoevered in Jasmine tests. It was fixed, but that test is
failing so it was marked specifically to be skipped when all VideoAlpha tests run.

For some reason the "muted" icon was not showing. Styles have been corrected.Now on focus background color is also simplified for div
.volume control.

When a VideoAlpha is present on the page, if the user tries to tab through out the entire page, eventually he will land on the VideoAlpha controls. The tab index order has been set up so that all control receive focus eventually in the order from left to right. When a control receives focus, it is hilighted. The last tab focuses the captions dialog. When the captions dialog has focus, the Up and Down arrows can scroll it up and down.