Simplified the callback API.

1. Callbacks will always be called if required is present and all other rules pass.
2. If required is not present and the field is empty, a callback will not be called.
3. If the conditions in #2 are met, a callback will be forced to call if it is preceded by a !.
[fixes #81] Wrapped default in quotes.
[fixes #78] Fixed an issue with multi checkboxes.
Updated the version number.
A faster way to write a for loop. It caches the array size, so we don't need to recalculate the size at every iteration.
Add bower.json
v1.3.1
Merge pull request #90 from brenopolanski/master

A faster way to write a for loop. It caches the array size, so we don't need to recalculate the size at every iteration.
Merge branch 'bower' of https://github.com/porada/validate.js into porada-bower
Updated the copyright notice.
Merge remote-tracking branch 'upstream/master'