The environment now holds some useful info.

That is, the project root and distribution dir root.
The BaseContentProvider now stores and accepts a 'type_options' dict.

It will store arbitrary objects that need to affect the specific
instance of content loader.
Added a command transformation procedure in the Environment class.

It executes a command and logs it.
The Jinja2ContentProvider needs to return the file it installed!
Added a scss generator.
Cleaned up the main entry bit. It's cleaner, simpler, shorter and more documented!