Add Event timers and supporting utilities (+ lint and fmt)

[f5yacobucci]

Proposed changes

• minimal bindings for events (nginx_event_t and company)
• getters for request status and subrequest depth
• cycle count increment
• flags as argument to subrequest
• subrequest can accept a custom data
• do not automatically nuke the subrequest body. that should be up to the caller.

[ivanitskiy]

@f5yacobucci Please remove links to not publicly available repositories.

[f5yacobucci]

@f5yacobucci Please remove links to not publicly available repositories.

Can do, can you point me to an example? I'm not seeing one at the moment. Should just be nginx.org dev guide links, but I'll continue to scrub.