Add dummy and LevelDB database backends
Make it compile
Merge remote-tracking branch 'proller/next_tools' into next
Merge remote-tracking branch 'sfan5/leveldb' into next
Merge remote-tracking branch 'proller/liquid63' into next
Merge remote-tracking branch 'proller/math' into next
Merge remote-tracking branch 'proller/json' into next
Merge remote-tracking branch 'proller/weather' into next
Merge remote-tracking branch 'proller/liquid_send' into next
Merge remote-tracking branch 'proller/liquid_default' into next
Merge remote-tracking branch 'proller/huge_cave' into next
Merge remote-tracking branch 'proller/weather_fog' into next
Merge remote-tracking branch 'proller/wingsuit' into next
Merge remote-tracking branch 'proller/collision' into next
Merge remote-tracking branch 'sapier/avoid_facedir_if_not_moving' into next
Merge remote-tracking branch 'sapier/modmgr_fixes' into next
Merge remote-tracking branch 'proller/clouds' into next
Merge remote-tracking branch 'Zeg9/slippery' into next
Merge remote-tracking branch 'MirceaKitsune/sun_moon_coloring' into next
Merge remote-tracking branch 'khonkhortisan/diagonal_rail' into next