Fix harfbuzz assertions using patch from Chromium.

Exotic text (e.g. attempting to render a binary file such as .zip
or .exe as a webpage) can trigger an assertion failure in the
Harfbuzz code. Chromium developers also noticed this issue and
committed a patch to fix it:

http://lists.freedesktop.org/archives/harfbuzz/2009-August/000354.html

This patch has not been accepted by upstream, but this (old) version
of Harfbuzz has been abandoned and superceded by Harfbuzz-NG.

Issue #11264
fixed compile errors for no-JIT configuration

Issue #11475 https://github.com/ariya/phantomjs/issues/11475
Import GhostDriver v1.0.4

Issues in this release: https://github.com/detro/ghostdriver/issues?labels=1.0.4&state=closed
See GhostDriver Changelog for more details.
CONTRIBUTING.md: convenient => confident

Minor correction to language use in CONTRIBUTING.md
Add require.paths support

Issues: https://github.com/n1k0/casperjs/issues/462 https://github.com/ariya/phantomjs/issues/11339
Getting ready for 1.9.2.

Issue #11452: https://github.com/ariya/phantomjs/issues/11452