Support all the versions and more!

• Update form script
• Update Consul client configuration to match architectural diagram
• Improve form error output
• Switch from notion of "extra configuration" to "common configuration"
• Add initial version-specific common configuration template stubs
• Have fun with "Technical Specifications" (remember the roots!)
• Add support for supported Vault docker image versions (0.6.1-CURRENT)
• Add support for supported Consul docker image versions (0.6.0-CURRENT)
• Update documentation