Essentially this is to remove the need for Raphael in inline dialog.
Arrow will simply be omitted for IE8, same as with the tailed dropdown.
- replace svg implementation with CSS arrow
- remember to test offset options, positioning for top/right/bottom/left arrows, etc; it will probably be simplest to create a solution that sits inside the existing arrow element as that's already got positioning logic
- review https://ecosystem.atlassian.net/issues/?jql=project+%3D+AUI+AND+component+%3D+%22Inline+Dialog%22+AND+resolution+%3D+Unresolved+ORDER+BY+priority+DESC%2C+key+DESC to see if any issues can be closed as obsolete