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
See: https://github.com/minetest/minetest/issues/1525
Background
Wuzzy2: If you attempt to spawn a L-system tree with minetest.spawn_tree, you can make Minetest crash if it is attempted to pop an empty stack.
ShadowNinja: This shouldn't cause a segmentation fault, but it should throw a Lua error
Commit Description
This commit throws a Lua error instead of causing a segmentation fault. The server will still "crash" but will include a Lua backtrace.
L-Systems fix randomness
Unless a random seed is provided (via Lua treedef) seed the PRNG with a different seed for each tree
Resolves: https://github.com/minetest/minetest/issues/1469
Fix l-system crash when treedef random_level not set by Lua
Config settings:
profiling = true/false (gather statistics)
detailed_profiling = true/false (break mod times to callbacks)
Chat commands:
save_mod_profile saves current statistics in debug.txt and shows on console (on default loglevel)
Add DPI support for statbar
Move heart+bubble bar to Lua HUD
Add statbar size (based upon an idea by blue42u)
Add support for customizing breath and statbar
This makes a number of changes:
* Remove the dependency on marshal by using string.dump and loadstring.
* Use lua_tolstring rather than having Lua functions pass string lengths to C++.
* Move lua_api/l_async_events.* to cpp_api/s_async.*, where it belongs.
* Make AsyncWorkerThread a child of ScriptApiBase, this removes some duplicate functionality.
* Don't wait for async threads to shut down. (Is this safe? Might result in corruption if the thread is writing to a file.)
* Pop more unused items from the stack
* Code style fixes
* Other misc changes
