Made the elevator sound audible again (#1052).
New feat: Use snow or ice to create loam in the foundry.

Two callbacks added:
IsLiquid - return a string with the material that this object consists of.
GetLiquidAmount - return how many material pixels this object is worth.
Repaired ice hit sound.

"CrystalHit?" -> "GlassHit?"
Documentation added for DigOutObject callback.
Added new callback: DugOut(object object_by).

Called in a new object that is created from digging out material.
Reactivated EditCursorModeToggle key (formerly Space) now set to no key.

Can be set in KeyConfig.txt as requested by Sven2.
Fix crash on DugOut callback if an unloaded definition is referenced in material Dig2Object.
Deathmatch goal ends game when all but one player (or team) leave (#893).
Merge branch 'master' of ssh://git.openclonk.org/openclonk
Fixed clonk freezing in mid-run when building loam bridges (#943).
Removed 4 lines of useless code.
Fixed restart rule (#1072).
Require semicolon after 'do' loop

This makes C4Script consistent with C-based languages, and current usage
on master shows that in the majority of cases, the author expected to have
to place a semicolon after the loop anyway.
Fix grenade launcher ammo check