Extension:GuidedTour/Upstream change

This is the process if you want to send a change through Gerrit to upstream Guiders:

As a one-time thing, do:


 * 1) git remote add jeff-optimizely git://github.com/jeff-optimizely/Guiders-JS.git
 * 2) Clone the uptream Guiders repo on GitHub, so you have https://github.com/username/Guiders-JS
 * 3) Add this to your local repo:
 * git remote add username git@github.com:username/Guiders-JS.git
 * That will let you fetch upstream from GitHub, and (later, after Gerrit review) do pull requests.

Then, for each new change you want in upstream:


 * 1) Get the latest from upstream to your local repo.
 * git fetch jeff-optimizely
 * 1) Start a local branch for your change.
 * git checkout jeff-optimizely/master -b improvement
 * 1) Before actually doing anything, push this branch to Gerrit without review:
 * git push gerrit improvement
 * 1) Do your commits as normal.  If it doesn't generate a Change-Id, do:
 * cp other_repo/.git/hooks/commit-msg .git/modules/externals/mediawiki.libs.guiders/mediawiki.libs.guiders.submodule/hooks/
 * then do:
 * git commit --amend
 * 1) When you have progress you want reviewed on Gerrit:
 * git push gerrit HEAD:refs/for/improvement/improvement
 * The second string is the Gerrit topic.

Once your change passes review, it will automatically get mirrored to our GitHub. Until then, the branch will still be there, but with only the upstream code. When the Gerrit change is approved:


 * 1) Send it to your GitHub fork:
 * git push username improvement
 * 1) Send improvement as a pull request to upstream.