Our base RelatedObjectSelectorView had a regression where selected

objects would not longer render properly. This happened because we

introduced a new renderSelectedOption() which defaults to calling

renderOption(), but we forgot to actually pass the item to

renderOption() here. This change fixes that.
This change also updates the remove icon for objects in the related

object selector to be our standard Ink delete icon. And we enforce the

hover/not-hovered colors for the icon, which fixes a bug with Review

Board's related user selector where the icon's hover color was blue due

to being a link element.

Ran JS unit tests.
Tested using the user, group and repository selector widgets.