Introduce oom plugin and disable syslog plugin

The oom plugin is improves handling of out-of-memory conditions
in gears by dynamically adjusting a cgroup's memory limit while
cleaning up its tasks.
Remove an incorrect comment line in oom_plugin
Disable OOM kills for gear cgroups
Add OOM_CHECK_PERIOD to oo-watchman man page
Fix typos in rsync commands
Bug 1099835 - Add missing require
Merge pull request #5432 from UhuruSoftware/rsyncfix

Merged by openshift-bot
Merge pull request #5429 from a13m/oom-plugin

Merged by openshift-bot
Bug 1099772 - Add message for unidle on secondary gear
Merge pull request #5433 from jwhonce/bug/1099835

Merged by openshift-bot
Merge pull request #5434 from jwhonce/bug/1099772

Merged by openshift-bot
Automatic commit of package [rubygem-openshift-origin-node] release [1.25.2-1].
Automatic commit of package [rubygem-openshift-origin-msg-broker-mcollective] release [1.25.2-1].
Automatic commit of package [rubygem-openshift-origin-controller] release [1.25.2-1].
Automatic commit of package [rubygem-openshift-origin-console] release [1.25.2-1].
Automatic commit of package [openshift-origin-node-util] release [1.24.2-1].
<mongodb cart> adapt to use SCL-provided mongodb

Bug 1073126
https://bugzilla.redhat.com/show_bug.cgi?id=1073126

Adds `lib/mongodb_context`, which wraps MongoDB executables with
appropriate SCL context
mongodb_contetxt
`nohup` command needs to be wrapped by `mongodb_context`
Add update_configuration function

Sets up `PATH`, `MANPATH`, and `LD_LIBRARY_PATH` for shell env