[Development] [FYI] the new way to retarget gerrit changes

[Oswald Buddenhagen]

On Mon, Sep 12, 2016 at 02:39:57PM +0300, Orgad Shaneh wrote:
>    Either extend the sanity bot, or create a new bot, which listens on
>    gerrit's event stream.
>    If the change's owner (or an approver?) posts a comment reading "Please
>    retarget <branch>", run your script on the server side. You need some
>    sanity test that ensures this branch exists etc...
> 
... which he implemented, and it's deployed now.

for simplicity, only the change owner may issue the command. for other
cases, you still need to go through an admin. the same is advisable for
batch requests, but do as you wish.

the regex is 

  /^(?:gerrit-)?bot:\h*(?:please\h+)?move\h+(?:back\h+)?to\h+(?:branch\h+)?([\w.]*\w)\b/im

which boils down to "bot: move to <branch>" at the start of any line of
a gerrit cover message.