Adds functions that allows adding new paths to the synchronisation.
When writing the new paths to the file if a parent directory is
synchronised all the childrens are removed.
This creates a new optionnal category in the config called other that is
used to configure various aspects of unison.
Currently it only allows to customise the path to the cache directory
which is ~/.unisync by default
This refactors the paths functions in a class called PathsManager
allowing to share some data like the Paths to the various directories
unisync works with.
This commit also creates the get_paths_to_sync method which simply reads
the paths file and returns its content as a list
Adds the mount_remote_dir method to the synchroniser, this allows to
mount the remote directory in order to access it with the generated
links.
Also adds the background parameter to the documentation of update_links
The paths file will be used for everything related to the paths to
synchronise.
Adds the user_select_files functions that allows the user to select
paths
