ajaxorg/cloud9 — pull request #2987 by FreedomKnight (2013-10-23 18:49:32+00:00)
Title: inverse direction of tabNext, tabPrevious and add tabn, tabp

i think tabNext in vim is go right, so i turn it right.
and i also add tabn and tabp command which function are same as tabNext and tabPrevious.
(there's also in vim)