added rw_server and rw_client to gitignore
Revert "added rw_server and rw_client to gitignore"

Files in the directories with the same name could not be added anymore into git, as git gets confused between the directory names and the executable names

This reverts commit 579c6575ac259a2c21e25692e25e24df77f6321a.
repwatcher.conf: clarified the usage of process_identity and server_process_identity