system arch guide docs - update gear directories
Make READMEs in template repos more obvious

https://trello.com/c/dKJfwLdh - origin_cartridge_170

Also, remove unnecessary .gitkeep files and replace duplicated
'ruby/versions/{1.8,1.9}/template/.openshift/*' files with
directory symlink to 'ruby/versions/shared/template/.openshift/'.
Merge pull request #5451 from VojtechVitek/improve_template_repo_readmes

Merged by openshift-bot
Automatic commit of package [rubygem-openshift-origin-node] release [1.25.5-1].
Automatic commit of package [openshift-origin-cartridge-jbosseap] release [2.18.2-1].
Automatic commit of package [openshift-origin-cartridge-jbossews] release [1.24.2-1].
Automatic commit of package [openshift-origin-cartridge-postgresql] release [1.25.2-1].
Automatic commit of package [openshift-origin-cartridge-jenkins] release [1.22.2-1].
Automatic commit of package [openshift-origin-cartridge-mock] release [1.20.2-1].
Automatic commit of package [openshift-origin-cartridge-php] release [1.25.2-1].
Automatic commit of package [openshift-origin-cartridge-python] release [1.25.2-1].
Automatic commit of package [openshift-origin-cartridge-jbossas] release [1.25.2-1].
Automatic commit of package [openshift-origin-cartridge-diy] release [1.23.2-1].
Automatic commit of package [rubygem-openshift-origin-common] release [1.24.3-1].
Automatic commit of package [openshift-origin-cartridge-ruby] release [1.25.2-1].
Automatic commit of package [openshift-origin-cartridge-perl] release [1.24.2-1].
Automatic commit of package [openshift-origin-cartridge-nodejs] release [1.26.2-1].
Automatic commit of package [openshift-origin-node-util] release [1.24.4-1].