Revert "RF-13585: drop components demo"

This reverts commit 581ee62c6b6f6d877fcadaaf707e1eda2e70076d.
RF-13585: Replaced xmlns:r="http://richfaces.org" definitions
RF-13585: Replaced r: prefix with a4j:prefix
RF-13585: Replaced r: prefix with rich: prefix
RF-13585: Re-factored the component-demo package names
RF-13585: Fixed the broken components-demo link sample
RF-13585: Simplified the components-demo deployable name, dropping the version