Use extra bit in Location

[joto]

The Location stored in Osmium has 32 bits each for the latitude and for the longitude. The longitude goes from -180° to +180° and needs all the 32 bits, but the latitude only goes from -90° to + 90°, so there is one extra bit that could be used for other use cases.

This issue is about whether we want to change Osmium to expose that extra bit in some way and how exactly wo do that. It is created as replacement for the closed PR #394 .