D12177: Make some frameworks optional so okular can be built on Android

[Albert Astals Cid]

aacid requested changes to this revision.
This revision now requires changes to proceed.

REPOSITORY
  R223 Okular

REVISION DETAIL
  https://phabricator.kde.org/D12177

To: apol, #okular, aacid
Cc: aacid, michaelweghorn, ngraham