[ANN] global header move on Tuesday 2013-04-23 between 1200UTC and 2000UTC

Hi,

as discussed on the ESC the global header move script is at:

 https://gerrit.libreoffice.org/#/c/3367/3

and worked fine on Linux, and the plan is to execute it on master if it is
building on all platforms and if there is a proper advance warning. This is
that warning. ;)

I rebased the change on master today only to find master not even building from
scratch on Linux because of test failures. Because of that I didnt even try to
set the gerrit buildbot on it, and instead used the last known good state of
master (the one I pushed it the script to gerrit with), executed the move and
scheduled a gerrit build agianst that:

 https://gerrit.libreoffice.org/#/c/3465/

That build succeeds on Linux and Windows, but fails again on OSX *sigh* due to
as it seems another unrelated master breakage, preventing me _again_ to check
if this works on all platforms. So this has to be played into the dark
unfortunately.

I plan to execute the global header move on Tuesday, 2013-04-23, hoping that
the weekend changes are merged on Monday and the master is in a reasonable
state then. The plan is as follows:
- I will rebase the script against master on 2013-04-23 1200 UTC and again
  execute and trigger the build on gerrit
- if that succeeds, I will push'n execute the script on 2013-04-23 2000 UTC 
  expecting it was not broken by intermediate commits
- if the tinderboxes did not finish in time, I will only wait for OS X as the
  other platforms have been proven to work on other master states already
- if that fails for reasons obviously based in the script itself, I will check
  if I can fix/workaround the issue or if the move needs to be postponed --
  thats what we have the buildbot for
- if it fails on a platform and it becomes apparent its because master was
  broken on that platform before, I WILL execute the move anyway. 
- If you broke master on a platform by the time of the move, I fully expect YOU
  to fix that up, even with the extra pain of the header move.

tl;dr: Dont break master, but especially dont break master on 2013-04-23!

Master will of course stay open for all as usual, but remember that:

a/ If you have doubts of any kind, you can just push to gerrit to get a testbuild
b/ Even if you do not get a testbuild, you can simply "park" your commit on
   gerrit to merge/cherry-pick it to master on Wednesday after the move
c/ http://www.youtube.com/watch?v=4XpnKHJAok8&feature=player_detailpage#t=1399s
   "... people make 1-liner changes, knowing it cant POSSIBLY break, right?"
                                          "(audience giggles uncomfortably)"
   Please avoid doing so -- in general, but even more so on Tuesday ;)

Best,

Bjoern