Start off a new history from FIREFOX_17_0_5esr_RELEASE.

We don't need the full mozilla history as much as we want the repo to be
small and pushable to github via HTTPS. For studying purposes, the full
history is always available upstream.
Merge upstream version FIREFOX_17_0_5esr_RELEASE.

Note that this will not bring any history as one might expect -
it was stripped down to reduce the repo size and make it pushable
via HTTPS to github.