flavor enhance zap downwards/upwards when hiding

flavor enhance zap downwards/upwards when hiding
 Changes to be committed:
	modified:   doc/fixes35.0
	modified:   include/extern.h
	modified:   src/apply.c
	modified:   src/zap.c

    On 3/23/2015 6:41 PM, a bug reporter wrote:
    > When you're hiding under an item (e.g. via garter snake polyform), and
    > that item gets polyshuddered into nonexistence, you continue hiding
    > (under nothing).
    This was addressed previously.

    > (Incidentally, it's a bit weird that you use > to aim at items that are
    > flavorwise above you at the time.)

    This addresses the flavorwise concern.