[DF-4885] Image splitter improvement. Code cleanup.
[DF-4885] Image path initialization fix
[DF-4885] Small refactoring
[DF-4885] Fixed file reopen bug
Merge branch 're_stable' into DF-4885_imagesplitter

Conflicts:
	Tools/ResourceEditor/Classes/Qt/Settings/SettingsManager.cpp
	Tools/ResourceEditor/Classes/Qt/Settings/SettingsManager.h
Merge branch 'DF-4885_imagesplitter' into re_stable