* This method is "hard-coded" and not configurable yet.
* Prevent throwing and teleporting into blocks directly, prevent
the second throw on glitching into a one thick ceiling (might lead to
lots of passable violations at present).
* If stuck in a block with the feet (not sand/gravel) without being on
ground, throwing is prevented.
* Some dependencies were updated, hopefully without conflicts for
backwards compatibility (untested).
Allow all blocks that get the IGN_PASSABLE flag set but which the player
can stand on to be ground from height 0 on (GROUND_HEIGHT, takes
effect unless for blocks with an explicit workaround). Set IGN_PASSABLE
and GROUND_HEIGHT for ENDER_PORTAL_FRAME explicitly.
Seems better to have a dedicated module for this as well, since other
modules might be built against different versions of the Bukkit-API,
potentially.
