FIX: Fixes #163
- Admin users can now _always_ select edit icon.
- Fixes odd by-product of b0f42ebf: userHasAccess() couldn't ref $this->getTarget().
- Fixes CSS to correctly show 'disabled' GridField 'edit' icon.
Merge pull request #168 from phptek/issue/163

BUG: Fixes #163 User unable to select pending workflow instances with the "edit" icon