Previously it depended on addFolder() / removeFolder() calls to adjust
watchers when new folders were added or removed. There also needed to be
complex move handling.
Now, any folder creation/move-in notifications automatically trigger
watcher additions and folder deletion/move-out triggers removal.
Add state and signal to catch the following two known problems:
* Linux: inotify user watch pool is exhausted. Folder watcher becomes
unreliable.
* Windows: buffer is too small, some notifications are lost but watching
stays reliable.
This gives more insight about the logs and allow setting fine-tuned
logging rules. The categories are set to only output Info by default
so this allows us to provide more concise logging while keeping the
ability to extract more information for a specific category when
developping or debugging customer issues.
Issue #5647
This is not sufficient as it is not working for the Socket API.
Next commit will fix it in another layer.
Also, not ignoring paths that are not inside the folder is wrong
as it might still happen if the name has a different casing
This reverts commit d5a481f132.
Introduce a global ExcludedFiles instance to avoid loading the global
exclude lists several times.
One could still add per-folder exclude lists by checking these after
the global ones.
