Clean up, refinement, simplify v 0.13.0

Rename:

1. no css prefix
2. no ui prefix

Abstract Classes Added:

1. $control - Unity control height
2. $label - Layout of label
3. $list - Control list separators style(horizontal & vertical)
4. $alert - common alert style

Components Added:

1. view - control figure and caption layout(warn and no wrap)
2. image, icon
3. form controls: checkbox, radio, toggle, select
4. labels: brand, ribbon, magnet, bubble
5. tag - no gradient background button
6. separator - (rename form `divider`) more separator style
7. headline - unity headline style in `.h1` to `.h4`

Adjust Collections:

1. nav, tab, board, pagination extend form $list
2. fieldset - remove unnecessary details
3. flash, notice - extend form $alert