Update pref screen

Fix message when relink images
Add separator on storage screen
Update relink image to support big images
update relink image logic, small bugfixes
Fix isMissing flag for redlink chapter
Add free space checker for backup images
Update external page handling
Update jsoup to 1.7.3`
Fix update service for external page
Update progress bar style for content and image
Fix external page refresh
v1.1.12-beta
Minor improvements

Update+Minor improvements
small translation fixes
Merge pull request #98 from Trollmen/patch-1

Patch 1 for Polish