Bug 1160752 - Make apache-vhost more atomic

* Write one buffer to file rather than a number of write
* Truncate conf files rather than removing them to ease up httpd
  failures on restart
* Have watchman XXX plugin clean up "deleted" configurations
Bug 1160752 - Add Watchman plugin to clean up vhost configurations
Revert "bz1151744 - wrap the wait for reload to finish inside of the lockfile"

This reverts commit dc07a6d177263a128f9b1506db9a7a20e64df451.
Revert "bz1147054 - use common lockfile"

This reverts commit 1cab19a4a88b0717b5199fcf85d148217ff198ca.
Bug 1160752 - Make Watchman frontend cleanup period configurable
Merge pull request #5932 from jwhonce/bug/1160752

Merged by openshift-bot