vhost-plugin: switch from rewrite back to proxypass

Switch the primary traffic proxy for the vhost frontend plugin.
There are still other RewriteRule's that do the setting of
variables, etc.
Bug 1053485 - Changing GID_MIN in login.defs prevents app creation

This patch was originally submitted by Josep 'Pep' Turro Mauri <pep@redhat.com>
vhost-plugin: remove keepalive=On for now
Bug 1075673 - Unable to perform git deploy after binary deployment

After doing a successful binary deployment, the node is unable to
process a git deployment
Merge pull request #4850 from vbatts/408-3-rewrite_to_proxypass

Merged by openshift-bot
Add support for multiple platforms in OpenShift.
Changes span both the broker and the node.

Add a setting named 'NODE_PLATFORMS' to broker.conf.
Add an optional attribute named 'platform' to cartridge manifests.
Add an optional 'Required' attribute for the 'Scaling' key to cartridge manifest.

Broker queries nodes of all platforms when building its cartridge cache.
Broker does not allow group overrides for cartridges of different platforms.
Broker uses the cartridge platform to filter nodes based on the 'kernel' fact.

Node handles the case when a web proxy cartridge is not collocated with a web cartridge.

Modify tests to take new logic into account.
Add tests to cover new code paths.
Bug 1074627 - Improve error handling and make more robust

* Improved error handling
* Added cgroups thawing
* Added man page
* Attempt to kill off processes with several methods
Fix broker extended
Merge pull request #4945 from jwhonce/bug/1074627

Merged by openshift-bot
Fix "create scalable app with custom web_proxy" test expectation.
Fix getting cart from CartridgeCache in the context of an application.
Merge pull request #4946 from danmcp/master

Merged by openshift-bot
Adding test coverage
Merge pull request #4943 from bparees/binary_deploy

Merged by openshift-bot
Merge pull request #4947 from danmcp/master

Merged by openshift-bot
Bug 1007830 - Better error handling around quickstarts.json loading
Merge pull request #4933 from brenton/BZ1053485

Merged by openshift-bot
Bug 1067008 - Guard gear delete from missing Cartridge IDENT
Merge pull request #4948 from danmcp/master

Merged by openshift-bot
Merge pull request #4949 from jwhonce/bug/1067008

Merged by openshift-bot
Merge pull request #4944 from UhuruSoftware/master

Merged by openshift-bot