added optional groups to route syntax, with tests

[ianstormtaylor]

from the ideas in #1508

[willium]

I'd love this to be merged, @documentcloud can we get this in?

[jashkenas]

Very nice. Can we use Rails' parentheses syntax instead of brackets for the optional parts? Make that change, and maybe add the little bit of docs about this to index.html, and I'll be glad to merge.

[ianstormtaylor]

makes sense, i'll make that change very soon. thanks!

[ianstormtaylor]

okay, switched to parentheses. added a section to the docs, and also broke up the route examples into the docs into separate paragraphs since it was getting very complicated to follow along after adding the third example.

[jashkenas]

Mind rebasing against master so there's a clean merge?

[ianstormtaylor]

sure thing, all rebased and updated test names to match.

[jashkenas]

Thanks a bunch -- beautiful patch.

[braddunbar]

Fantastic. This also allows optional trailing slashes, which I think will make a good many people happy.

routes: {
  "route(/)": "route"
}

[ultimatedelman]

this is phenomenal. thanks, @ianstormtaylor

[fredsterss]

@ianstormtaylor yeah boi!