Add option to disable bed's night skip - Solve second point of #512 by adding a setting, `enable_bed_night_skip` , with default value of `true`.

- beds/Changelog.txt probably won't be updated because http://dev.minetest.net/Changelog is used instead
- The information in farming/API.txt is already documented in game_api.txt

Add commented-out 'node river water' lines to all biomes

Add extinguish sounds (from default mod lavacooling)
'disable fire' setting extinguishes fire quickly using a dedicated ABM
'disable fire' also disables all other ABMs
Simplify flammable node removal ABM
Speed up node ignition, it was too slow
Add 'sunlight propagates = true' and 'paramtype = "light" to flame
Balance fire sounds' gain

Mgv5/mgv7 papyrus schematic now has sand nodes as a base
Add sand beach to mgv5/mgv7 deserts

Increase chance value of ABMs
Disable ignition from a distance
Only detect neighbouring extinguishing nodes
Fix code style issues and add comments

By CProgrammerRU
Also, by paramat:
Slightly raise base of collision box
Improve code style

Make replace ABM optional, disabled by default

-> Don't always drop the main mushroom (allowed endless spore generation loop before)
-> Drop less spores, before you got lots of spores

Code re-arranged and clarified

More complex distribution of dry grasses
Remove water below glacier rivers
Gravel as glacier seabed
Do not force-place acacia root
Tune acacia tree density
Match mgv5/v7 mushrooms to tree density
Spawn mgv6 mushrooms by trees

It should alias the old name (mese_block) to the new/current name (mese) rather than the other way round.