make delete icon less intrusive again, only on hover
use background image instead of img for Files delete icon
remove unnecessary tipsy for Files delete
use new delete icon for deleted files as well
fix delete button not showing in IE8
Explicit ie8 fallback
Merge branch 'master' into delete-fix

Conflicts:
	core/css/styles.css
Replace delete icon with spinner
fix loading.gif size for both upload and deletion, force visiblity
force show loading icon also for IE
Merge pull request #4113 from owncloud/delete-fix

Delete icon fix