OSS Document Scanner

### Features
- brightness / contrast support
- While importing PDF you can now choose to import each page as an image or each PDF images
- setting to force confirmation of document detected region (happening while not in batch mode)

### Bug fixes
- use image format and compression from settings for all app operations. If using PNG it will mean app data will be bigger
- wrong layout with navigation bar on some devices
- re-factored settings to make it a bit easier to find document naming format
- crash while croping images
- brightness / contrast fix. The algo was wrong. it means your current values might get unwanted result (if you changed brightness/contrast). Really sorry you need to change them again
- many image cache update fixes
- reseting image crop would end up with wrong zone
- better image quality of documents list view
- action buttons layout fix on main view for better readability
- camera layout fix after new batch button with label
- dont show live document detection if it is disabled
- many webdav sync issues