D20991: [FsTab] Add cache for device file system type

[Stefan Brüns]

bruns marked an inline comment as done.

REPOSITORY
  R245 Solid

REVISION DETAIL
  https://phabricator.kde.org/D20991

To: bruns, #frameworks, ngraham, hallas
Cc: kde-frameworks-devel, michaelh, ngraham, bruns