Refactor tools/init.d scripts

1. The scripts try to write lock files to /var/lock/subsys, which is owned by root. We should change this location to be somewhere that doesn't require root access.

2. The actual run command does an su to the CHUKWA_USER which also caused problems for us. It seems like it would be cleaner to not embed the su calls in the script, but instead allow the user to su when they run the script (which worked much better for us). That way everything done by the script would be done by the same user.

3. Each script has CHUKWA_HOME, CHUKWA_CONF_DIR and CHUKWA_USER hard coded. Hard coded defaults is ok, but the ability to override them without modifying the scripts would be ideal.