Changes:
- This GLEP can stand independently of GLEP58.
- Add XZ to compression types list.
- Move cutoff to 32KiB. Provide size example w/ 32KiB+gzip.
- Split specification into generation and validation.

-- 
Robin Hugh Johnson
Gentoo Linux: Developer, Trustee & Infrastructure Lead
E-Mail     : robbat2@gentoo.org
GnuPG FP   : 11AC BA4F 4778 E3F6 E4ED  F38E B27B 944E 3488 4E85