apk cache sync fails on ro storage

lbu already supports ro mounts. Would be nice if we could implement such feature also for apk.

(from redmine: issue id 512, created on 2011-01-09, closed on 2011-07-11)

• Relations:
  • relates #588 (closed)
• Changesets:
  • Revision 415e230a by Timo Teräs on 2011-03-16T12:56:13Z:

db, cache: automatically remount cache read-write when needed

.. and back to read-only after finishing with modifications.

fixes #512