Make osmium_time work on Windows.

osmium_time outputs wallclock time and user/system time, the latter is not
available on Windows. With this change only wallclock time is reported which is
the most important anyway. On unix systems you can set
REPORT_USER_AND_SYSTEM_TIME when compiling and it will also report the other
values.
Fix haversine formula
Prefer prefix ++ to postfix ++
Move string-to-int conversion into types.hpp

This way they are all in one place and it is the same place where the necessary
types are defined. This also adds a definition needed for compiling on Windows.
Remove references to sqlite lib/Update README.

The sqlite lib wasn't used any more.