Add a SelectAndDelete Token deletion mode

[xrigau]

What this does is: When you press the delete key it'll first select the
token on the left to the cursor and then pressing the delete key again
will actually delete the token.

Del -> Select the token -> Del -> Removes the token

Demo using the SelectAndDelete mode

[mgod]

I like this fix, but it shouldn't be a deletion style. This should just be how it works if the TokenClickStyle is selectable (returns true from isSelectable()).