`chef-gem` software definition

This software definition is mainly for installing an embedded chef gem
inside server projects like `chef-server`. This definition will also
install all chef bin files into `INSTALL_DIR/embedded/bin` vs
`INSTALL_DIR/bin` in order to better hide embedded library from the
external system.
omnibus-ctl 0.0.6

New version picks up chef-solo from PATH, which is properly configured
any time a *-ctl subcommand is invoked.
Merge branch 'embedded-chef-via-gem'