added OldPath field to Event struct for MOVE and RENAME, updated Stri…

…ng method and tests

Fix retrieveFilelist for the instances where files are deleted in

between retrieving file names and stat during filepath.Walk

Merge branch 'dev' of https://github.com/radovskyb/watcher

Merge branch 'dev' of https://github.com/radovskyb/watcher

updated README

updated README

run command in separate goroutine to prevent block

updated README

added some small tests