imap with two keys consumes first key input

[MichaelMackus]

If I have a mapping like this in vimb:

imap jk <Esc>

And I insert "j" into an insert field, it doesn't insert anything at all (even if I continue to insert other non "k" characters afterwards). I have to insert "j" twice in order to insert 1 character.

This is inconsistent with how VIM works. In VIM, if I have the above mapping, and I insert the "j" character it "waits" to see if the next character inserted matches the map. If it does not, it successfully inserts the "j" character (as well as the next character inserted).

[MichaelMackus]

Closed, see #258