Add OO mechanism across all components v 0.14.0

1. Unity class naming (ALL CAPS)
2. Group all abstract classes to 'share/class' directory

New variables:

1. $textfield-min-height - Effect the content height of component.
2. $component-inner-height - The larger one between $py-line-computed and
$textfield-min-height.
3. $component-outer-height - Component content height with outer padding gaps
and border width.

Feature adjusted:

1. Remove .indent-left-* and .indent-right-*, only and set default indent width
as 20%(a column width in elastic-grid.css)
2. Extend default modifiers(e.g. .mini, .naked) in labels, .icon, .message,
headline and .breadcrumb.
3. Unity component height for every base component.Major of them got extended
.mini modifier.

New components:

1. .pointer
2. .tip
3. .progress

Rename components:

1. .cover => .mask