Add ZLIBWAPI_DLL and LEVELDB_DLL CMake options Remove legacy MINGWM10_DLL CMake option Update 32-bit buildbot (OpenAL updated, zlib updated) Change build directory for buildbots to '_build' to prevent removal of Android build files Use -win64 suffix for 64-bit Windows builds Fixes #1476

Fixes https://github.com/minetest/minetest/issues/1514

Fix android makefile to provide a correct dummy githash if detection fails

Improve error handling in saveBlock()

There have been plenty of ppl involved in creating this version.
I don't wanna mention names as I'm sure I'd forget someone so I
just tell where help has been done:
- The partial android versions done by various ppl
- Testing on different android devices
- reviewing code (especially the in core changes)
- testing controls
- reviewing texts

A big thank you to everyone helping this to be completed!