Bug 980253 - Map illegal versions to 0.0.0

* Raising exception broke CDK which uses illegal version numbers
Installation instruction updates
Bug 984609 - fix a narrow condition where sshd leaves a root owned process in the frozen gear cgroup causing gear delete to fail and stale processes/
Use oo_spawn for all root scoped shell commands

Revert previous changes which replaced oo_spawn calls with ApplicationContainer.run_in_root_context.

The oo_spawn method was intentionally designed to be the single execution path for all shell executions,
for security and clarity. Adding a second execution path to oo_spawn not only results in multiple ways
to do the same thing, but having such a method in ApplicationContainer specifically promotes creating
unwarranted/undesirable dependencies on ApplicationContainer where no dependency was previously
necessary.
Merge pull request #3096 from jwhonce/wip/cartridge_version

Merged by openshift-bot
Improved Rakefile; added changelog
Merge pull request #3101 from nhr/updates

Improved Rakefile; added changelog
Merge pull request #2721 from BanzaiMan/install-doc-updates

Merged by openshift-bot
Merge pull request #3100 from rmillner/BZ984609

Merged by openshift-bot
Merge pull request #3099 from ironcladlou/dev/node-fixes

Merged by openshift-bot