use an imagemap for the "fork me on github" ribbon

[ivanov]

Right now, the ribbon on the front page blocks out the possiblity of clicking
on the "Index" link, because the "Fork me on Github" link is on top of it.

I've rectified this by providing an imagemap, which only makes part of the
image clickable as a link. I've verified that it works under Firefox, Chromium,
and w3m.

I have also moved the ribbon from being only on the front page, to
appearing on all pages, since that has the potential of inviting
contributors more actively, as most people won't spend much time on the
index page, once they are actually using matplotlib, whereas they will
be peaking at the gallery, as well as the api docs, etc.

I got the numbers for the ribbon from here: susestudio/studio-help#20, but then
adjusted them so that the full upper left triangle would be clickable, and not
just the ribbon.

Also, can someone tell me if I should be filing this only against master, only against 1.2.x, or both?

[pelson]

Thanks @ivanov - nice solution to the problem!

I think we probably would want to do this against v1.2.x, would you mind changing the PR appropriately?

Cheers,

[ivanov]

@pelson - did this in #1474, but it seems that this change should be applied both to master and v1.2.x...

...unless I'm severely confused about how are we working now - will things from 1.2.x be merged back into master?

Edit: also, I didn't find a way to switch which branch a PR is applied against, so I had to open a new one anyway.

[dmcdougall]

will things from 1.2.x be merged back into master?

Yup.

[ivanov]

ok, thanks for clarifying, @dmcdougall, closing this in favor of #1474, then.