Some function results have been casted to void to silence a clang-tidy
warning. We are ignoring the results from IO operations because we can't
do anything useful in those cases anyway.
This adds a copyright notice to all C++ files and the README clarifying
the license. (There is no change of the license.) This also removes a
few names explicitly mentioned as copyright holders, instead refering to
the git log which has a full list of all osm2pgsql developers. (There is
also still the AUTHORS file which names the most important developers.)
The only exception is the sprompt.cpp file which was taken from
PostgreSQL and keeps its original license information (and, of course,
the files in contrib).
Just run them on the liechtenstein file and make sure they don't fail.
The places.lua example is not run because it needs a Lua json library
which might not be available everywhere.
