Performance boost

[asoseil]

We should try to use rwmutex to unlock files locked by fsnotify in order to boost commands performance.

[ghost]

@Asoseil We can try to require the lock on the project files but I can imagine that the effects of this solution are:

• better performance of the command (execution time)
• same time for the user

The total time needed by realize to run the command remain the same because in the end to lock all the project files the routine need to wait the unlock of fsnotify.

Probably there's not a way to improve the global performance without stop fsnotify watcher.