Bug 975708: Fix jboss java7 marker regression

Due to a regression introduced by c3e63de3c7f84cd62df99634dc58371cfd19fd6c, the initial java7
configuration was not being updated properly during setup. Newly created apps using the buggy
cart will default to java6 until the next Git push, at which point java7 will be correctly
enabled.

Fix setup logic to correctly configure java7 for new applications.
Beef up cron cart README
Merge pull request #2896 from ironcladlou/bz/975708

Merged by openshift-bot
Merge pull request #2897 from BanzaiMan/cron_cart_readme

Merged by openshift-bot
Hook documentation updates
Merge pull request #2898 from ironcladlou/dev/documentation

Merged by openshift-bot
Automatic commit of package [openshift-origin-cartridge-cron] release [1.8.3-1].
Automatic commit of package [rubygem-openshift-origin-node] release [1.10.4-1].
Automatic commit of package [openshift-origin-cartridge-mysql] release [0.4.3-1].
Automatic commit of package [openshift-origin-broker-util] release [1.10.4-1].
Automatic commit of package [openshift-origin-cartridge-jbossas] release [1.3.4-1].
Automatic commit of package [openshift-origin-cartridge-perl] release [0.5.3-1].
Automatic commit of package [openshift-origin-cartridge-python] release [0.5.3-1].
Automatic commit of package [rubygem-openshift-origin-controller] release [1.10.4-1].
Automatic commit of package [rubygem-openshift-origin-console] release [1.10.4-1].
Automatic commit of package [openshift-origin-cartridge-jbosseap] release [2.4.4-1].