added windows system interface: moving, deleting renaming files;
some changes in path handling
added zip archives support
Merge branch 'win' of https://github.com/vojtsek/DirectoryViewer into win

Conflicts:
	DirectoryViewer.pro.user
	osinterface.cpp
merged win interface and zip
added creating folders
changed icons
Added opening files in other programs; persistent current selection
Added computing dir size, menu items, fixed some crashes