This privilege allows map protection bypassing for server operators
and world moderators.

Initially I had thought that bypassing protection mods would have been
something that could entirely be done inside mods and minetest_game,
but the concept of protection is defined in core, in the code of
core.is_protected().

I don't feel that it would be logical to introduce a protection
concept in core, but not some way around that for server operators
to maintain map parts that need fixing, de-griefing or cleanup.

Others had noticed the same problems, and proposed a patch to
minetest_game. That patch is fine by itself, but it fails to add
protection bypass functionality for digging normal nodes and placing
nodes.

So, instead, we indroduce the new priv "protection_bypass" in core,
and modify 'on_place_node' and 'node_dig' to allow bypassing node
protections if the player holds this priv.

This priv was tested with protector redo by tenplus1.

A followup patch to Minetest Game will include allowing special checks
for doors, trapdoors, chests in Minetest Game.

Protection mods will likely want to mimic the changes in their relevant
code sections.

We can just test for the presence of these settings nicely here,
no need to use a try / catch construct.

I've written several experimental bits of code that revolve around the
need for a consistent calendar, but implementing one is extremely hard
in mods due to time changes and mods overriding core.get_timeofday(),
which will conflict.

The second part of the problem is that doing this from a mod requires
constant maintenance of a settings file.

An implementation in core is trivial, however, and solves all of
these problems at virtually no cost: No extra branches in server
steps, and a single branch when minetest.set_time_of_day(), which is
entirely reasonable.

We store the day_count value in env_meta.txt.

The use case is obvious: This change allows mods to create an actual
virtual calendar, or properly account for seasonal changes, etc..

We add a "/days" chatcommand that displays the current day count. No
permissions are needed. It can only retrieve the day count, not
modify it.

* Replace string by-val passing with const reference
* Fix code style
* Remove redundant `int table` definition and indentation level

Throwing a LuaError calls destructors as it propagates up the stack,
wheres lua_error just executes a longjmp.

Missing `valleys` in `settingtypes.txt` and `minetest.conf.example`.

* Update OpenSSL (thanks @sapier, i use his patch!), Curl and SQLite3.
* Remove old arm config. Almost all phones that use ARMv5 have 1 core and 256-512 RAM, it's about 2-5 FPS.
* Do -O3 optimization for libs and remove -fexpensive-optimizations for Minetest (-O3 includes this! Read gcc docs).
* OpenSSL fix - thanks @sapier, again.

Increase maximum spawn altitude to reduce spawn issues.

Fixes #3764

This function could be used to steal insecure environments from trusted mods.

This still only supports 256 characters, but that's because
Irrlicht's clipboard handlers don't support wide characters.

keymap_console opens a full window for chat history browsing.

Fixed a minor mistake that made it appear as if the inventory
is serialized multiple times - once per each variable. In fact
it is serialized once per each node.

This reverts commit 60dc01dc.

This fixes issue #3773

Having a non-power-of-two image broke the Android app.

Lower water table where base humidity is low.
Alter heat and humidity to compensate for river humidity and altitude
chill.
Correct misuse of surface_max_y in generateTerrain.
Remove sand trails in the water at river mouths.
Remove river water below water_level.
Correct heat/humidity calculations where noises are less than zero.
Correct heightmap errors as much as possible.
Make humidity calculations more readable.

If the default value of a setting was empty,
it previously generated a trailing space.

Currently translated at 61.3% (483 of 787 strings)

(Merger of five commits)

Currently translated at 49.5% (390 of 787 strings)

(Merger of three commits)