backend: bootstrap program

[RoboSparrow]

bootstrap app in main(s)

• init() handler, validating globals and paths
• destroy() handler
• global struct app_state, containing thread independent vars
  • paths(base, session, survey, lock, log) - they may be customisable via globals in future
  • python module instance

This means a small uptick on initialisation, especially for single command line calls but decreases the lookups especially for demonised implementations

• move fcgi_accesstest logic