Before this fix, XCodeCapp always ran under /bin/bash, causing problems when trying to source the files from other shells, like /bin/zsh
This fix reads the shell information directly from the user's environment and XCC to run using that shell.
The first method (updateUserDefaultsWithLastEventId) just
sets the default while the other (synchronizeUserDefaultsWithDisk)
forces a synchronization with the disk.
This is a small fix that makes XcodeCapp update the latestEventId value
in the defaults database at the end of each FSEvents callback.
Prior to this fix, the synchronization was performed only when the user
actively decided to stop listening to a project.