Perf: Scalability

[mmd-osm]

Further scalability tests in 2017 on this branch:

Test case: [out:json];node(63174280);out; with node id continuously increasing for each request.
Up to 32 parallel processes via jmeter, runs on server (no network overhead)
Minutely updates + delta area update active.
Up to 12 FastCGI processes, managed by supervisord
Web server: nginx