follow df-structures change to drawBuilding
core: generate SC_WORLD_LOADED for arena too
add NEWS entry for arena SC_WORLD_LOADED
fix renamed pregnancy_ptr/mystery to pregnancy_genes/caste
Update xml definitions.
Fix crash due to incorrect loop bounds in add-spatter.

This caused a buffer overrun bug if an ADD_SPATTER
reaction had any non-improvement outputs.
Track readable names of vmethod hooks for diagnostic messages.

Note that this changes the ABI of all plugins that use hooks.
Fix a crash in beehive code if bees die with yet uncollected products.

http://www.bay12games.com/dwarves/mantisbt/view.php?id=6368
Merge branch 'master' of https://github.com/angavrilov/dfhack
Started working with adv-quest stuff