Sublime Text bundle -> TextMate bundle.
Move text editor related stuff into separate repositories.

Also, add a link to @rubik's vim plugin. Fixes #2.
Fix a link in the README.

Github doesn't auto-link to users in markdown files, apparently.
Eagerly evaluate `core.build` to make tracebacks more helpful.
Do not emit a line break before indented blocks.
Change the AST API.

 * All calls to the AST types should start with a location tuple.
 * Various sets of `Name`s are now global rathen than class-local.
Slightly improve handling of operator priority.
Remove a stray ' from the usage description.
Fix `ArrowPairs`.
Turn `a > b` on `Name`s into `b < a`.
Create a separate group for skipped tokens (again.)

Without that, the position of everything else will be incorrect.