Fix busted add_custom_css function.
Fix (and rename) add_css_filename.
Merge branch 'fix-custom-css'

Conflicts:
	cdk/__init__.py
Reordering --toc and --custom-css to match master.
Whoops. Fix missing comma.
Merge branch 'fix-custom-css'

Conflicts:
	cdk/__init__.py
Merge branch 'add-install-target'