initial load of bindonce, implementation for chat. performance has improved noticibly, but I think we need to do this in a few other places
Looked for opportunities to replace ngclass with boclass to improve performance, as well as replacing some instances of ng-if with bo-if
more optimizations with bindonce, replacing ngIf with boIf.
some of this was done with an axe rather than a fine brush, so there may be issues we need to be on the watch for.
Merge pull request #1885 from snicker/bindonce

Bindonce implementation