Also, add a spec to cover the loading of keymaps in `atom-spec` and
reset the `keymap`'s internal data after each spec gets run to prevent
test pollution with keymaps.
TextMatePackage is only designed to load resources out of a TextMate
bundle. It's used only at load time, and from that point out we only
refer to our own global `syntax` data structure to access the data that
it loads.
These changes are mostly aesthetic in nature. I just thought it would
be a good idea to have theme loading be parallel to package loading as
much as possible. So I localized more logic on the `atom` global.
Previously, we had a custom method on the `TextMateBundle` class for
retrieving these variables from the bundle. Now we're using Atom's
`syntax.getProperty` mechanism. The idea is to map TextMate concepts
to their Atom equivalent, rather than building everything directly
around TextMate.
The `load` method on the superclass will provide a general template for
loading the package's resource. Each subclass will be responsible for
loading resources in a manner appropriate for the package type. There's
some initial progress on loading TextMate settings as scoped properties,
translating the TextMate scope selectors to CSS-style atom selectors.
