Added: scaffoldery init, create, install, ls, preview and generate.

usage: 

<pre>
# list available generators and their platforms
$ ./bin/scaffoldery generate

# aggregated list of generators for the given platform on all installed packages 
# in the scaffold_templates directory (including those from different repos)
$ ./bin/scaffoldery generate angular

# generate the scaffold. currently outputs to console
$ ./bin/scaffoldery generate angular controller
</pre>