[Tails-l10n] Release schedule for Tails 2.4

Hi,

I'll be the release manager for Tails 2.4, which is a major release
scheduled on 2016-06-06. The list of tickets targeting Tails 2.4 can be
found here:

    https://labs.riseup.net/code/projects/tails/issues?query_id=193

Here's the preliminary release schedule for Tails 2.4:

* 2016-05-25:
   - Feature Freeze: All feature branches targeting Tails 2.4 should
     be merged into the `devel` branch by noon, CET. I'm open to make
     exceptions if you can be online and responsive during that
     afternoon, but ask me first!
   - Build and upload Tails 2.4~rc1.
   - Start testing Tails 2.4~rc1 during late CET if building the image
     went smoothly.

* 2016-05-26:
- Finish testing Tails 2.4~rc1 by the afternoon, CET.
- Release Tails 2.4~rc1.

* 2016-06-06:
  - All branches targeting Tails 2.4 *must* be merged into the `testing`
    branch by noon, CEST.
  - The upcoming Tor Browser is hopefully out so we can import it.
  - Build and upload Tails 2.4 ISO image and IUKs.
  - Hopefully start testing Tails 2.4.

* 2016-06-07:
- Finish testing Tails 2.4 by the afternoon, CEST.
- Release Tails 2.4 during late CEST.

Testers, please let me know:

* if you are available on 2016-05-25, late CEST

* if you are available on 2016-05-26, morning to afternoon, CEST.

* if you are available on 2016-06-06, late CEST

* if you are available on 2016-06-07, morning to afternoon, CEST.

Cheers!