replace variable length arrays with std::vector

I have prepared the most direct version of std::vector-instead-variable-c99-array, intentinally not changing the signatures. I hope you'll introduce vector parameters etc. in more  consistent way than I can.

The final steps to support Windows is the described array change and https://github.com/openstreetmap/osm2pgsql/commit/7d780c931c209f539c84e7d02a8f12f2a81e4d67 inclusion (done in master but not here).

Could you please run ``make check`` on Linux? On Windows I have 8 rounding errors, one UTF8 error and one ``Projection code failed to initialize`` (will solve it by configuring environment).
It is used for some printing int buffer:
https://github.com/alex85k/osm2pgsql/blob/array-to-vector/middle-pgsql.cpp#L795