Implemented compilation for client:true and added wrappers for AMD and JST

[mereskin-zz]

It is sometimes desired to use Jade templates client-side, e.g. in Backbone apps. Jade compiler supports "client: true" mode, which produces javascript function, which can be called client side.

To use jade templates client-side you have to change extension to .js, and add one of the wrappers: amd or jst. AMD wrapper will create AMD-compatible module in the specified destination file to be used with require.js.

jade: {
  files: {
    'tmp/jst/jade.js': ['test/fixtures/jade.jade']
  },
  options: {
    client: true,
    wrapper: "amd"
  }
}  

JST wrapper will extend global JST object with template function. Template name can be processed with processName(srcFile). Compiled template then can be rendered simply by calling window.JST["templateName"](data):

jade: {
  files: {
    'tmp/jst/jade.js': ['test/fixtures/jade.jade']
  },
  options: {
    client: true,
    wrapper: "jst",
    processName: function(str) { return str.match(/^test\/fixtures\/(.*)\.jade$/)[1]; },
  }
}  

[tkellen]

Hey Andrey,

Thanks for taking the time to submit this PR, it looks really nice! We have added this to another of the contrib-series tasks already and I'd like to keep it consistent--could you please see gruntjs/grunt-contrib-handlebars#24 for our preferred implementation?

Also, we won't be supporting RequireJS within any of the templating tasks themselves, as you can perform the optimization using grunt-contrib-requirejs. You can even do it in one step after configuring an alias task, if you like.

[mereskin-zz]

Ok, Tyler, I will check it out.

[tkellen]

@andreym Have you had a chance to check out the handlebars task?

[mereskin-zz]

Yes! Sorry, I was overloaded by the work. Will submit changes tomorrow.

[tkellen]

Awesome, thanks!

[mereskin-zz]

Here you go!

[tkellen]

Hey Andrey, I need to rebase this against the current master, as it is now, merging your PR would require re-writing our history. Otherwise, I think this looks good!

[jessedijkstra]

Exactly what I was looking for! Been missing this since I switched from grunt-jade to grunt-contrib-jade. Any ETA when this will be merged in and put on NPM?

[tkellen]

ping @mereskin

[gvn]

Bump! +1

[mereskin-zz]

Completed rebase.

[tkellen]

Added you to AUTHORS and published as 0.5.0. Hugely useful PR, thanks a TON Andrey.

[mereskin-zz]

You are welcome!