A bit more on the knife. Also add missing files to CMakeLists

Data for copying throwing knife to Land once it hits.

Bring back sorting

Bring icons back

Set default collision mask for gears at currenthedgehog X/Y to FF7F, expose mask to scripting as well. This should resolve the collision part of bug #420

Further work on moving to players list model

Simplify file loading procedure

Start moving to players list model.

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- Fix warnings and hints - Hide "Converting the operands to Int64 before doing the add could prevent overflow errors" kind of hints as pretty useless and annoying