[ ] implement the tree_view context menu commands.

[ ] optimization of the add_folder operation: if the command supports all the
    requested options add the folder directly instead of reading the folder 
    and adding the content in chunks.

[x] Add with wildcard.
	Add with wildcards options :
	1) Include sub-directories.
	2) Ignore directories that are symbolic links.
	3) If the selection is "*" --> ignore backup files.

[x] Drag & Drop.

Other archive formats:

[x]	rar
[x]	lha