MW2 Android v0.0.2-alpha

A pre-release of the Android port, on top of v0.0.2.

Pre-release: this is published as one, so it is not offered as "the latest
release" and the in-launcher updater will not move anyone onto it. Install it
from the apk attached below.

Highlights

• Release tags with a suffix are now read. v0.0.2-alpha was a tag the
  launcher's update check could not parse at all, so it answered that the newest
  version "is not one" — as every v0.1.0-alpha.N before it went unoffered.
  Tags are now compared as semantic versioning orders them
  (0.0.2-alpha < 0.0.2-beta < 0.0.2 < 0.0.3-alpha), and what is not a version
  is refused rather than ordered somewhere.
• Faster software block-compressed decoding on Mali and Adreno, which is
  the path every BC texture takes where the driver cannot sample it: BC2
  10.1 → 4.7 ms and BC3 7.1 → 6.4 ms per 2048x2048 decode, output byte for byte
  unchanged.
• The apk says which release it is: 0.0.2-alpha (commit), in place of
  "1.0". versionCode is 16, so it installs over v0.0.2.

Also

• The release workflow now refuses a tag that is not a version before anything
  is published, and drafts a suffixed tag as the pre-release it is.
• tools/bc_bench.cpp (bc-bench) prints the decode timings quoted above.
• tests/version_test.cpp (ctest name version) holds the tag order.

Needs your own copy of the game: an ISO of the Xbox 360 disc, version 1.0.557.
The apk is built by the Build Android APK run this release triggers and is
attached here a few minutes after publishing.

Full history in CHANGELOG.md.