Move set-ets-values sexp to the correct category (thanks to Axem for finding this)

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10160 387891d4-d844-0410-90c0-e4c51a9137d3
Allowed shield_info_reset() to initialize shield_hit_info to empty values if it's not associated with a ship, as required by hudescort.cpp. Might fix Mantis #2961.

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10161 387891d4-d844-0410-90c0-e4c51a9137d3