Added support for multiple root folders

- not yet solved: identical subfolders in more than one root directory
create duplicate tree entries
Added more descriptive window title
Fixed issues with user-specific documents folders

- Detection of the "Documents" folder name is now independent of OS
localizations
Fixing line break issues
Merge remote-tracking branch 'upstream/devel' into devel
Solved problem with duplicate folder names in multiple root folders
Automatic language detection support for BGEE
More file types for mass exporter

- Mass exporter supports new BGEE file types now
- Open: Optional PVRZ -> PVR decompression
MassExporter update and compatibility fix in ResourceStructure
Merge branch 'devel' of https://github.com/Argent77/NearInfinity into argent77-devel