Add support for node-sass

[panga]

It's better to replace "compass" by "node-sass" because the second doesn't rely on Ruby/Compass Gem installed.

node-sass is based on libsass which is faster than any Ruby implementarion.

[kennethlynne]

Great suggestion!

[kennethlynne]

I will have to investigate that it does not differ in implementation in any other way and is not breaking anything, but this should be implemented.

[cmelion]

FWIW, my team found Compass installation had more issues when compared to "npm install sass". We also had to set up a separate task to run sass via "the command line" to make performance tolerable.

        sass: {                              // Task
            dist: {                            // Target
                options: {                       // Target options
                    style: 'compressed',
                    loadPath: '<%%= yeoman.app %>/bower_components/',
                    noCache: true
                },
                files: {                         // Dictionary of files
                    '<%%= yeoman.app %>/styles/main.css': '<%%= yeoman.dist %>/styles/main.scss'       // 'destination': 'source'
                }
            }
        },
        exec: {
          sass_dev: {
              command: 'sass --load-path <%%= yeoman.app %>/bower_components/ --watch <%%= yeoman.app %>/styles/ '
          },
          sass_dist: {
              command: ''
          }
        },

https://github.com/cmelion/generator-angular-cmelion/blob/master/templates/common/Gruntfile.js