renamed base_width parameter of built-in furry ball object to root_width.
cosmetics.
Fixed styling issue on disney material layer folding

The label which remained once a disney material was folded changed
position to the left of its inner layout. This made the folded
and unfolded layers unconsistent. Now the issues is solved.

Signed-off-by: Marius Avram <marius.avram1309@gmail.com>
Save folded disney material layer state between sessions

When a project will be saved the folding state will also be saved
in the project file as a simple parameter with the true or false
value.

The next time the project will be opened the parameter will be used
to fold the layers the same way as they were before appleseed.studio
was closed.

Signed-off-by: Marius Avram <marius.avram1309@gmail.com>
Merge pull request #495 from marius-avram/folding_improvements

Folding improvements
many improvements to the foundation/utility/commandlineparser module.

- added support for mandatory arguments.
- added error and warning counters.
- refactored the code.
Merge branch 'master' of github.com:appleseedhq/appleseed
added comments.
new makefluffy tool to grow hair on any scene.
Merge remote-tracking branch 'upstream/master' into est