open #208
Unit tested in both themes;
.s-icon-btn refactored slightly to focus on usage
as an icon-only element, removed overlap designations
with .s-btn in markup;
Colors normalized for theming;
Code cleanup;
open #95
Shadow and color normalization: fixed-position, tabular;
Updated paint bucket and icon-box in symbols font;
Custom checkboxes now use inset shdw;
WTD-1392
WTD-1360
WTD-1394
New minus symbol added to font;
Updated folder symbols art;
CSS tweaked for reset button (WTD-1394) and direction sign;
Font project file updated;
(cherry picked from commit f6c7d8e)
