* Non-int versions of `Point` and `Displacement`
This will allow us to make some structs, such as `ActorPosition`, much
smaller.
* ActorPosition: Use smaller types
`Monsters`: 56K -> 46K
* player.cpp: Reduce size of `DirectionSettings`
* CrawlTable: Displacement -> DisplacementOf<int8_t>
* CrawlTable: vector<vector> -> array<vector>
Also only allocate one vector during construction instead of two.
A bit less indirection.
* Monster#enemyPosition: Point -> WorldTilePosition
sizeof(Monster): 240 -> 232
* Monster: Further optimize field layout and sizes
sizeof(Monster): 232 -> 208
`Monsters` is down to 40,000 bytes
* DMonsterStr: _mx/_my -> position
Reduces the size of the `PathNodes` array from 28 KiB to just 8 KiB.
Also reduces the size of `pnode_tblptr` from `300 * sizeof(void *)` to
`300 * 2` bytes.
Introduces new functions to check for presence of and remove player items.
These functions do not rely on or expose item indices.
They're implemented as free functions instead of Player methods due to
complicated include dependencies between `player.h`, `inv.h`, and
`inv_iterators.h`. We should probably look into cleaning this up at some
point.
Previously this was falling back to FunctionCase, leading to inconsistent casing of class methods throughout the codebase. Applied to Item as an example.
Used when moving from one persistent variable to another where we want the source variable to be marked empty. Defining as a function instead of move constructor/assignment operator as we only really need to mark the source for xvalues. Detecting that in the constructor/assignment would be needlessly complicated.
This cleans up a bit of code and solves a few edge cases where an item
could be lost, the game be unresponsive, or miss fire an event during
lag cause of the cursor not reflecting the currently held item.