Added drag handle for sorting of tasks and projects

! Tags beginning with numbers now ignored (e.g. #1, #12)
! Drag tasks and projects by drag handle only now; allows task text to
be copied, more obvious feature
* Fixed a few IE9 CSS issues: borders on img elements, text-shadow
doesn't work, default to darker text instead
! Softened border line colour; plus small CSS refinements
! Removed brackets around the hit frequency numbers