If the max number of files limit is achieved when the application
is starting the StatusView is not yet configured so we cannot
show the warning.
We show the warning in the function scanning the directory only if
the StatusView is up. On the other side, when the application starts
it will check if the initial project dir hit the max files limit and
show the warning if needed.
Introduce a new field in items generated by TreeView:each_item()
to point "dir" to the toplevel directory entry.
In this was we can simplify the code and know if the toplevel
directory is files limited.
Since the directory monitoring is now basically working we remove the
project scan thread periodically scanning the project directory.
Each project's directory is scanned only once at the beginning when
calling the function `core.add_project_directory` and is updated
incrementally when directory change events are treated.
The config variable `project_scan_rate` is removed as well as the
function `core.reschedule_project_scan`.
Francesco Abbate