Mgvalleys: Remove riverbed sand placement from base terrain generation
Riverbed material placement moved to MapgenBasic::generateBiomes()
Document fields and add note that the biome API is still unstable
BiomeGen defines an interface that, given a set of BiomeParams, computes biomes
for a given area using the algorithm implemented by that specific BiomeGen.
This abstracts away the old system where each mapgen supplied the noises
required for biome generation.
The shadow bug at y = 63 was caused by dark air being placed as dust,
when the biome dust was unspecified it was falling back to 'air'
In dustTopNodes only dust == 'ignore' will disable dust placement
NodeResolver name lists now belong to the NodeResolver object instead of
the associated NodeDefManager. In addition to minimizing unnecessary
abstraction and overhead, this move permits NodeResolvers to look up nodes
that they had previously set pending for resolution. So far, this
functionality has been used in the case of schematics for
serialization/deserialization.
Move debug streams to log.cpp|h
Move GUI-related globals to clientlauncher
Move g_settings and g_settings_path to settings.cpp|h
Move g_menuclouds to clouds.cpp|h
Move g_profiler to profiler.cpp|h
Add 'absolute value' option to noise map functions
Extend persistence modulation to 3D noise
Extend 'eased' option to noise2d_perlin* functions
Some noise.cpp formatting fixups
