changed overlay to blur and white

Increase z-index in CSS 'dropdown-menu' class to 1060. The 'tablesorter > columnselector' will be hidden with 'qfq-sticky' by values < 1000.

Reduce z-index in CSS 'qfq-sticky' class from 9999 to 1000. The 'tablesorter > columnselector' will be hidden with values > 1060.

Implements #9203. Pin the header of table, to make it always visible even if there are a lot of rows

Bei FK, Form=request_fk, Pill 'Finanzen' ist der Abstand ziwschen einer Fieldset Ueberschrift und der folgenden Note massiv zu gross.

Refs #8204. Copy requiredPosition from Form to FormElement has been moved from 'formElementSetDefault()' to 'copyAttributesToFormElements()'

.icon-flipped (mirrors icon)
.icon-spin (icon spins once on hover)
.icon-spin-reverse (mirror of icon spin)