Update Chars app to use allocated ic_chars sprite when app window is iconised
Respond to Message_WindowInfo if it finds the required ic_chars sprite in the Wimp Sprite area,
otherwise just ignore it.
Notes:
- The sprite name is hardcoded.
Reason for Merge Request:
- Currently, Chars uses the generic
ic_?sprite, even though the correct sprite is available in the RISC OS 5 ROM Sprite pool.
Tested on:
- RISC OS 3.5 (using RPCemu)
- RISC OS 5.30 (using Raspberry pi 3)