Add drop command.

Signed-off-by: nppangband <nppangbanddev@verizon.net>
Merge branch 'Jeff'
Misc. changes in UI
Misc. improvements in targetting graphics
Misc. fixes
Adjust panel and others
Finished with panel adjustment
Improvements to targetting
Merge branch 'diego' of https://github.com/nppangband/NPPAngband_QT.git into Jeff