Remove DTIME macro and its uses, too

- Add warning log level
- Change debug_log_level setting to enumeration string
- Map Irrlicht log events to MT log events
- Encapsulate log_* functions and global variables into a class, Logger
- Unify dstream with standard logging mechanism
- Unify core.debug() with standard core.log() script API

- SRP: print the address only once, not twice
- Legacy: previously the address was not printed at all
- Make both messages structurally the same, to facilitate log analyzers

Player now spawns on julia set due to julia offset
Add commented-out '#include profiler.h' for timetaker use
Use v3fs to reduce number of parameters
Tune tunnel width to match mgv7

Fixes a bug where the old list ring remained when a new formspec
was displayed over the old one. This created the list-ring of the new formspec
to be partly ignored.

Thanks to @VanessaE to report the bug, and @DonBatman to produce the code that
exposed it.

Update copyright years in all mapgens
Add myself to copyright notices in mgv5 and mgv7

Previous statements were wrong.

Currently translated at 99.6% (277 of 278 strings)

Currently translated at 100.0% (278 of 278 strings)

Currently translated at 100.0% (278 of 278 strings)

Currently translated at 100.0% (278 of 278 strings)

Currently translated at 100.0% (278 of 278 strings)

Currently translated at 100.0% (278 of 278 strings)

Currently translated at 81.6% (227 of 278 strings)

Currently translated at 78.0% (217 of 278 strings)

Currently translated at 100.0% (278 of 278 strings)

Currently translated at 3.5% (10 of 278 strings)

Currently translated at 92.8% (258 of 278 strings)

Currently translated at 100.0% (278 of 278 strings)

Currently translated at 100.0% (278 of 278 strings)

Currently translated at 66.5% (185 of 278 strings)

Maybe it is better to describe allowed symbols instead of writing regex?

Currently translated at 46.4% (129 of 278 strings)

Currently translated at 99.2% (276 of 278 strings)

Currently translated at 100.0% (278 of 278 strings)

Currently translated at 98.9% (275 of 278 strings)

Currently translated at 98.9% (275 of 278 strings)

Currently translated at 98.9% (275 of 278 strings)

Currently translated at 98.9% (275 of 278 strings)

Currently translated at 0.0% (0 of 278 strings)

Currently translated at 100% (0 of 0 strings)

Created new translation.

Currently translated at 99.2% (276 of 278 strings)

This might break some mods, but it is important for all uses of the param2 to
be documented.

This doesn't need a serialisation version or network protocol version change,
as old clients will still work on new servers, and it is bearable to have
new clients getting non rotated plants on old servers.