fix pull request #469 - multiple '$' invent slots

fix pull request #469 - multiple '$' invent slots

Assigning a partial stack of gold to quiver (Qnn$) resulted in
an extra '$' slot in inventory, one for the unquivered part and
another for the quivered part.

Throwing a non-quivered partial stack of gold at self (tnn$.)
also resulted in an extra '$' slot after throwing at self was
rejected.

For the first case, reject the quiver-subset-of-gold attempt.
For both cases, recombine the two stacks back to original amount.

Fixes #469