Don't set m_removed on dead players (dead players are indicated by hp == 0). Local
damage flash is shown whatever the cause was (even from Lua set_hp). PlayerCAO
damage flash matches duration of local damage flash. Fall damage is dealt much more consistently (this is done by disallowing jumping when speed.Y is very negative, up to now jumping could sometimes negate fall damage)

Inventory menu (with dragging) improved. Crafting is now handled via a IACTION_CRAFT inventory action.

- Node placement code moved to Lua
- Mineral system removed (added default:stone_with_coal and default:stone_with_iron).
- MapBlock and MapNode serialization updated.
- Mapgen: Frequency of iron increased.
- node_dig callback and related changes.

The huge item definition and item namespace unification patch (itemdef), see http://c55.me/minetest/wiki/doku.php?id=changes:itemdef