Expose X and Y of killed mob to OnMobKillEvent script event (for slime split, etc)

Rationale:
    OnMobKillEvent invoked under PLAYER's RID - so using e.g. POS_X and
    POS_Y returns PLAYER's coordinates when kill occured. The only extra data
    available been @mobID - giving killed mob's type (class).

    However, to "split" slimes I need to spawn few new mobs right on location
    where kill occured - or some area around this spot, not player's X/Y.

This commit exposes 2 new variables set by server, @mob_X and @mob_Y
containing mob's X and Y coordinates when kill happened.

This is server-code change needed by relevant scripts.
Scripts itself would be landed a bit later to serverdata.

0 files changed, 0 insertions, 0 deletions