Add support for resizing crosh terminal.
Add support for resizing crosh terminal.

TEST=manual
BUG=chromium-os:25947

Change-Id: Ic38cd810bba9ab1824f6252f1a1f586fb2ec87be
Reviewed-on: https://gerrit.chromium.org/gerrit/15792
Reviewed-by: Robert Ginda <4419ac4e35d191308e944202d542b192188656d1@chromium.org>
Commit-Ready: Toni Barzic <f679c7fc1851c0786edcf4cb72893c06a872b4b5@chromium.org>
Tested-by: Toni Barzic <f679c7fc1851c0786edcf4cb72893c06a872b4b5@chromium.org>

chromium/hterm,chromium/hterm,chromium/hterm,chromium/hterm