Make a function to scan a folder

[JostTim]

Scanfunction (recusively):

• get all filenames in a set (relative paths)
• in a second time all dirnames in a set (relative paths)
• files sets , folders sets in a dir in two separate keys, with root as key too

Comparefunction (recusively):

• sets intersection : all matching files are raised to the user
• if no intersection, return False

Transfert_function:

• copies all files (option to cut) (create folder if necessary)
• create all empty folders that don't exist after that