fix overlay pic command in the script buffer

[vafada]

in kq1,

1. Plant the bean stalk.
2. save game.
3. restore game.
4. the bean stalk doesn't show up
5. move to a different room
6. go back to the bean stalk room
7. It now shows up

see video of the bug:

https://user-images.githubusercontent.com/285941/201479023-1e280054-dc14-4376-9e95-ea1cea5fa36c.mp4

the OverlayPic in the script buffer draws/overlay the pic to the view but doesn't actually render the updated pic.

just calling OverlayPicture(scriptBufferEvent.resourceNumber); should fix the issue

Also cleanup code

• fixed warning The field 'AgileForm.nullXML' is assigned but its value is never used
• delete unused priorityBitmap variable

[vafada]

attaching save game incase you want to reproduce the issue:

KQ1SG.zip

[lanceewing]

Looks good to me.