always show checkbox when selected, also in IE8, fix #1621
fix caret on installation page for IE
fix navigation icons SVG replacement, also hover and active opacity for IE
fix user delete button not showing in IE, another SVG replacement issue
no ugly border around checkboxes or radio buttons
only style text, password and search inputs like inputs, instead of using unsupported :not selector
exchange bright caret with dark triangle
Merge pull request #1683 from owncloud/ie-fixes

IE fixes