[hubugs] Pushed amd64 fstabilisation back 45 days

Waiting for upstream stabilisation of cov-core, and a usable html2text and httplib2.
Update metadata cache for upstream's eclass changes
[QA] Sync categories list
Merge branch 'f/keyword/amd64'

* f/keyword/amd64:
  [hubugs] Pushed amd64 fstabilisation back 45 days