[wishlist] Fix the lack of support for concurrent writes in the same file

Hello,

When modifying and rewriting portion of a file already opened in PyRoom (for example, with an other editor to do spell-checking or such), there is no notification that the file has changed. It occasionally leads to data loss and is particularly worrisome with auto-save feature enabled.

I think it would be valuable to monitor file changes and propose to the user to reload the new version of the file.

I'm sorry I do not have time to provide a patch myself.

Regards,
Tony