Grunt: Add JSHint support.
Fix JSHint warnings.
Enable JS strict mode.
Enable `curly` rule.
Enable `forin` and `freeze` rules.
Update JSHint rules.

Enabled:

* `immed`
* `newcap`
* `latedef`

Removed:

* `boss`
* `laxbreak`
* `validthis`

Also move `bitwise` to fingerblast.js since that's where it's only needed.
Run `grunt`.
Merge pull request #379 from twbs/jshint

Add JSHint support and enable strict mode