Add all color schemes. Fix stylesheet order. Add import for color schemes.
The Customize menu now has all the base color schemes and switches properly
between them. The stylesheet loading function now loads wp_enqueue_scripts
instead of wp_head, which messed up the order. Switching schemes does not
destroy other customizations.
An @import line has been added to the variables.less file for each color
scheme, so now switching between them is more sensible.
Add Help folder. Self-contained bootstrap page.
Remove excess Dashboard and Widget page widgets. Add setup Dashboard widget.