Restrict this version to Android >= 2.3
Partially revert < 2.3 compatibility mode

This reverts part of 46675dfdcb4c7b511b4c35e4a2242e47d4678fd4. However,
since this commit did some cleanup and simplifications, we keep them.
Remove now useless changes to RxJava
crowdin: New translations
Merge pull request #3718 from rsudev/crowdin_translations

crowdin: New translations
Version code and changelog
Typo correction
fix #3721: NPE in Geocache.hashCode()

Also, hash codes must be equal when the objects compare equal. Since
equality compares only geocodes, the hash codes must also only take
geocodes into consideration.
Merge branch 'release' into upstream