Enhanced Directive Parsing

More ways to add directives to your manifest files
-
Support for comment blocks (in CoffeeScript, JavaScript and CSS) which makes the directive parser understand comments like the following:

```
/* Multi-line comment blocks (CSS, SCSS, JavaScript)
 *= require prototype
 or like this
 = require underscore
 = require_directory awesome/controls
 */

### Multi-line comment blocks (CoffeeScript)
 = require libs/prototype
 = require_directory controls
###

// Single-line comment blocks (SCSS, JavaScript)
//= require awesome

# Single-line comment blocks (CoffeeScript)
#= require awesome
```