#114 Extended Drop w/filter forgets filter

[Buddha Buddy]

While doing an extended drop "D" and you turn on a
filter (eg. "+" for books), as soon as you drop an
item, the filter is no longer in effect, even though it
is still listed in the filter field.

Workflow:
1. Start a new game
2. Enter Extended Drop "D"
3. Enable filters "/"
4. Filter on something in your inventory that you have
multiples of ("/" for missiles)
5. Hit <TAB> key to get back to menu
6. Drop the first item in the list "a"
7. Notice that you are back to listing your entire
inventory, even though your filter from step 4 is still
listed in the filter field.

Expected Result:
It should only list the remaining items that you were
originally filtering on.