Compiler support

[0xEAB]

It would be nice if there was compatibility information available.
This would allow downstream packagers to bundle redub with historical releases, too.

I assume, each release supports the latest stable compiler release at the time of its release.
But which versions are actually supported?

Other projects:

• (dm)d-tools reuses the tags from DMD. Very easy to match.
• LDC pins the version to be bundled via a file for…
  • (dm)d-tools
  • dub
  • reggae
  • other stuff