Allow AngularJS module name configuration and singlequotes in javascript objects

This additions make some formatting and style changes to comply with [jshint](http://www.jshint.com/). It also,

* Adds a `module` attribute to the `default.options` object that allows custom names of the `angular.module` generated by `ngconstant`.
* Adds a new `singlequote` option that generates javascript objects using single quotes (`false` by default).
* Renames task `shared_config` to `sharedConfig` to comply with _camelCase_ javascript convention (logs out a warning if the former is used).