Don't show splash if "checkForUpdates()" was called from menu
- also don't show it when starting freshly
Fixed infinite loop on new home tab.
Fix height computation for home and sections and titles.
New source structure
[Code clean-up] 'bookmarks' & 'commands'
Fixed, Disabling bookmarksManager completely when bookmark file has I/O errors.
Don't apply background image, when it doesn't exist.
Used Qt::ElideMiddle for treeWidgets.

- also set tooltips for their items
Added "Apply" button to Settings dialog.
Fixed, create  "default" album if albumList is empty or default album doesn't exist.
Fixed updating caption after 456155e3