Add some jQuery UI 'sortable' interaction styling

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5120 2fea6a4d-a838-0410-917b-93a53c48e9d2
Add HiDPI (SVG) jQuery UI icon sprites

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5121 2fea6a4d-a838-0410-917b-93a53c48e9d2
Update Textile to v2.5.1.

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5122 2fea6a4d-a838-0410-917b-93a53c48e9d2
Merge remote-tracking branch 'upstream/master' into new-search-widget