Update revealToggle - use it to trigger allMessages

`revealToggle` now takes an optional `slide` attribute, which triggers jQuery animations. Might further enhance this to allow customizations of the animations, right now it only used slideUp/slideDown, but not a priority at the moment.

The navbar button to display all messages makes now use of the `revealToggle` and its slide attribute. Much more sensible directive to use here, than the hacky contextMenu solution we had before.