Access to OneGate from remote locations

[vholer]

Few issues related to miniONE with Edge (and not only):

• OneGate binds to 127.0.0.1
• OpenNebula provides ONEGATE_ENDPOINT with private network IP
• also, front-end on EC2 doesn't detect public IP address correctly:
  • EC2 metadata service could be queried or
  • use curl ifconfig.co for general purpose
• probably also missing test for REPORT_READY in miniONE microenvs