Add test for watching individual files
Add test for unlink of watched file

gh-9
Add test for watching non-existent file

gh-105
Fix watching non-existent file in subdir
Minor refactor on non-existent file handling
Prevent fs.watch random events making test fail

occasionally get an extra change on add.txt here
need even more time
Test for unlink, then re-add
Test ensuring only the watched file emits events
Refactor options.persistent handling
Refactor new tests' cleanup code