Ignore .DS_Store in watcher

[partap]

I've noticed over the last few days that it seems like just about every time I save a file and my page reloads, it pauses for a few seconds and then reloads again (usually just as I'm clicking on a button to test or something).

I finally got frustrated enough to track it down...looks like mimosa-live-reload is sending too many refresh messages (on OS X, at least).

For example, if I save my file, assets/javascripts/moduleName/module.coffee, the main watcher sees it and compiles it to public/javascripts/moduleName/module.js. Then the live-reload watcher sees the compiled file and sends a page refresh message. Then about 5-6 seconds later, it sees updates to public/javascripts/.DS_Store and public/.DS_Store and sends 2 more page refreshes.

Easy fix would be to pass an ignored option for .DS_Store files to watch.watch().
...or go all out and add an exclude member to the liveReload configuration section. Not sure there are really any other common cases like this, but I suppose there could be...always nice to have a config option :)