Fine-grained item filters for informers

[Cordarion the Grey]

For example, it could look like gv.inventoryCountLike(regex, mask = 0x0), where regex is (case-insensitively) matched against every item in an inventory and mask is zero or more of the following flags, |ed together (which must all hold for a match to succeed):

• 0x1 — a non-bold.
• 0x2 — any bold.
• 0x4 — a non-activatable.
• 0x8 — any activatable.

[Cordarion the Grey]

Self-assigning.

[Cordarion the Grey]

Resolved in pull request #4.