rework the way "build targets" are handled

[mklabs]

right now the grunt help output is pretty verbose, that's due to the bunch of tasks added by the plugin.

Plus, there's quite a few alias right now that maps the ant-build-script build targets (basics, text, buildkit, minify and the default one).

I'm thinking of slightly reworking this to work with a single "top-level" task which takes task arguments to trigger the appropriate series of tasks:

$ grunt build # default, similar to `grunt`
$ grunt build:<target> # with target one of basics, text, minify and buildkit)

when an invalid target is passed in, then print the list of valid target.

also each of these build targets (really equivalent to alias) would have a pre and post "steps", where intro clean mkdirs always run before each build target, and copy ends the process.

The way intermediate/ publish/ are handled should slightly change too. Before hitting the relevant tasks (basically after mkdirs) change the grunt.file.setBase to the intermediate directory, and have the current working directory switched back to its original value right before the copy task.