Fixes #3196. Before, we didn't throw an error, and the engine thought the
block isn't occupied. But in fact it might be that redis is still loading,
and the block does exist in the database. The result was a cheesy map.

Why doing things simple ? Use pointer instead of strings to save players and remove them.
Saving players by name does a lookup to find pointer we already have ! Idem with removePlayer
Also remove unused removePlayer(peer_id), it's never called

... and remove trailing whitespace.

Thanks to @kaadmy (NeD) for pointing this out.

-> Don't pass pointer to whole IGameDef to NodeMetadata constructors
	and deserializers, but only to IItemDefManager, which is needed
-> Remove the unused content_mapnode_get_new_name() method
-> Fix style for MapBlock::deSerialize and MapBlock::deSerialize_pre22,
	improving accuracy of error messages a bit
-> Fix style at other serialisation methods too
-> Improve accuracy of some comments

Use std::queue instead of std::set, we don't need such a heavy container.
Don't convert position to int to convert it back to float in the next function.

Document the node metadata changes of the commit (serialisation version >=23):

704782c9 "WIP node metadata, node timers"

The legacy code added in commit

d879a539 - "Add minetest.swap_node"

for sending the whole mapblock to older clients on the case of a node
modification with swap_node, had the problem that the block chosen to be
sent to the client was referenced with node coordinates and not with
block coordinates, resulting in getting the wrong block sent to the client.

Borders have to be converted into BS format in order to be accurately comparable to
object positions.

Entity positions are serialized as F1000. Disallow placing
entities outside safe borders with the minetest.add_entity
call.

Note that this patch only enforces those boundaries for
placing entities, moving entities that move outside boundaries
aren't affected.

Thanks to @nanepiwo for pointing this out.

Remove unusable fine rotation by param2
Remove unused and redundant code
Fix code style issues

Fix regression since commit:

915807f8 "Rename doc/mapformat.txt and update doc to match SRP changes"

And add an underscore to doc file name to make it more readable.

1. Do two renames:
	* SER_FMT_CLIENT_VER_LOWEST -> SER_FMT_VER_LOWEST_WRITE
	* SER_FMT_VER_LOWEST -> SER_FMT_VER_LOWEST_READ
Now the two define values are consistently named with the _WRITE defines
SER_FMT_VER_{HIGHEST,LOWEST}_WRITE, and to better point out what the two
serialisation versions actually are for.

2. wrap some lines in doc/worldformat.txt, and point out that the node
timers are serialized at a later point, as this can cause confusion about
what now happens (if one doesn't strictly read the if block's conditions).

3. some whitespace fixes in NodeTimerList::serialize, and one new comment.

The documentation file contains not just information about the
map itself, but also about further files inside the world's
directory.

Documentation didn't reflect recent SRP addition, now it does.

Modders are now able to select the range of ore column height,
and the midpoint at which they 'grow' starting from.
This commit adds three new parameters for the 'sheet' ore type:
column_height_min, column_height_max, and column_midpoint_factor.
clust_size is now deprecated for this ore type.

After this, it should hopefully not record line numbers anymore,
so the diffs of updatepo.sh runs are smaller. Well, this is theory,
lets see how it will turn out to be in practice.

Currently translated at 100.0% (270 of 270 strings)

Currently translated at 91.1% (246 of 270 strings)

Currently translated at 100.0% (270 of 270 strings)

Currently translated at 100.0% (270 of 270 strings)

Currently translated at 98.1% (265 of 270 strings)

Penerjemahan

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Currently translated at 97.7% (264 of 270 strings)

This is a combination of 9 consecutive commits by the same author.
Their messages in chronological order are:

Translated using Weblate (Indonesian)

Currently translated at 79.2% (214 of 270 strings)

Translated using Weblate (Indonesian)

Currently translated at 80.0% (216 of 270 strings)

Ini merupakan istilah dan tidak perlu diterjemahkan

Translated using Weblate (Indonesian)

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Penerjemahan

Translated using Weblate (Indonesian)

Currently translated at 94.8% (256 of 270 strings)

Penerjemahan

Translated using Weblate (Indonesian)

Currently translated at 95.9% (259 of 270 strings)

Mencari persamaan makna

Translated using Weblate (Indonesian)

Currently translated at 96.2% (260 of 270 strings)

Penerjemahan

Translated using Weblate (Indonesian)

Currently translated at 96.6% (261 of 270 strings)

Mencari persamaan makna

Translated using Weblate (Indonesian)

Currently translated at 97.0% (262 of 270 strings)

Penerjemahan

Translated using Weblate (Indonesian)

Currently translated at 97.7% (264 of 270 strings)

Istilah tidak diterjemahkan

Currently translated at 73.7% (199 of 270 strings)

Currently translated at 90.7% (245 of 270 strings)

Currently translated at 100.0% (270 of 270 strings)

Currently translated at 44.8% (121 of 270 strings)

Currently translated at 100% (0 of 0 strings)

Created new translation.

Currently translated at 100.0% (270 of 270 strings)

Currently translated at 100.0% (270 of 270 strings)

Currently translated at 100.0% (270 of 270 strings)

Currently translated at 100.0% (270 of 270 strings)

Currently translated at 95.5% (258 of 270 strings)