You can now pick up gold in frail corners

[AdamPlenty]

Fixes #1517

[Loobinex]

The cursor is now problematic:

On the above image, the cursor is over subtile 8, close enough to the gold on subtile 7 to make it flash. Now the cursor says you mark the slab for digging, the flashing object says you pick up the object,... and what happen? Nothing, if you click nothing happens.
Hover over subtile 7 and you can pick up the gold, but the cursor shows digging. Hover over subtile 9 and you can mark for digging correctly.

Requirements:

1. Cursor should always match the action that happens when the player clicks.
2. Objects should only flash if you can directly interact with them

[AdamPlenty]

player->thing_under_hand should be cleared when a tile is highlighted for possible tagging.

[AdamPlenty]

player->thing_under_hand should be cleared when a tile is highlighted for possible tagging.

Indeed, I cannot reproduce your issue, at least on water. How do I get frail path corners?

[Loobinex]

Above report only applied when already with gold in hand.