Update warning at the top of the ABP for Firefox and Chrome devbuild listings

[fhd]

Background

Both the ​ABP for Firefox and the ​ABP for Chrome devbuild listing pages have a warning on top, however, we don't mention the fact that the standalone devbuilds don't work anymore, and that people now need to install them from AMO and the CWS respectively.

What to change

Explain the situation outlined above on the devbuild listing pages. Exact texts to be determined.

[sebastian]

Replying to fhd:

we don't mention the fact that the standalone devbuilds don't work anymore

This isn't accurate. On Chrome they still can be installed (by dragging the file into the extension management page). But they might get disabled when restarting the browser. Not sure about automatic updates either. Similarly, on Firefox AFAIK, they also still work when you disable signature checking in about:config.

So for these, who have to use older builds (i.e. testers), saying that those simply won't work would be confusing. But on the other hand, we should still make it clear to people that just want to try out the devbuild, to install the latest version from the CWS or AMO.

[philll]

The link to older versions of ABP for Firefox dev builds at ​https://adblockplus.org/en/development-builds#installation was already changed to ​https://addons.mozilla.org/addon/adblock-plus/versions/beta so we should maybe think about getting rid of ​https://downloads.adblockplus.org/devbuilds/adblockplus/ completely?

[sebastian]

It's probably not worth removing the self-hosted devbuilds (or just that page) for Firefox. In rare situations (e.g. if there is an issue with AMO) it might actually be helpful. But, except fhd or trev have more arguments, I don't mind too much.

[fhd]

The only thing I can think of these would still be useful is for testing older devbuilds. That did come in handy sometimes, and I don't think that's possible on AMO or the CWS. I would lean towards keeping them around for that purpose, but wouldn't mind all that much if they disappear either.

[sebastian]

Testing older devbuilds is something we regularly do, if it's only to test the update from an older build to the latest. However, it seems that as for AMO, you can still get older builds from there (see the link philll posted). The CWS on the other hand, doesn't let you download previous versions. So it's really only about old devbuilds for Firefox. But since we still need to host old builds for other platforms like Chrome, it probably doesn't matter whether we keep them for Firefox as well.