Add a Way of checking for specific Feature with Lua Adds minetest.get_feature() and minetest.has_feature()

Fix health bar overlap when a larger texture is used

Improvements to get_all_craft_recipes (see api doc)

Spawn single particles or make use of ParticleSpawner for many randomly spawned particles.
Accessible in Lua using minetest.spawn_particle and minetest.add_particlespawner.
Increase Protocol Version to 17.

Conflicts:
	src/clientserver.h