Add toggle case action to inline color editor

For #9519 (I just realized that issue only asked for Hex values...)

I know this will be post-1.0, but I wanted to go ahead and get this in.

### Features ###
* New "U" button for toggling between uppercase and lowercase versions for RGB, HSL, and Hex (where applicable) values
* Preserves case between value conversions
* Related code updated to be case-insensitive
* New tests for conversion, with all existing tests passing
* Also did some minor code style fixes

This code is rather confusing (as already documented), so it was a bit of a challenge to get this written up. I once spent 30 digging around in various places for a one-line fix.

Now for the issues present here:
* I cannot get the button to receive the `selected` class when the conversion is toggled. I've tried every trick I can think of to no avail.
* This requires an update to [TinyColor v1.1.0+](https://github.com/bgrins/TinyColor/releases/tag/1.1.0), included with this PR. The creator refactored the library quite a bit since the v0.9.10 version currently used. TinyColor also unconditionally converts input to lowercase, which would make us have to keep track if the input is uppercase or not (which, in line with the previously documented issues, would be very hard because of the changing types). I have worked with Brian on the aforementioned patch to store the original input, which in turn makes this patch much easier to work out.

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![change-case-button](https://cloud.githubusercontent.com/assets/3382464/4781305/b6bcb13e-5c96-11e4-91fc-4dbeff9f6495.png)
I should probably write this as `return color !== color.toUpperCase() ? color.toUpperCase() : color.toLowerCase();`, but doing so always messes up the output (as I'll explain).