perf: #[inline] small functions

[Liamolucko]

I've added #[inline] to a bunch of small functions. This about doubled my project's framerate, specifically due to Vector math.

Also, the crate was failing to compile due to #[deprecated] being placed on some impl blocks, which seems to be invalid.
I was getting this error:

error: this `#[deprecated]` annotation has no effect
   --> src/geom/shape.rs:224:1
    |
224 | / #[deprecated(
225 | |     since = "0.4.0-alpha0.5",
226 | |     note = "Use another collision library like `vek` instead; please comment on issue #552 for use-cases other libraries don't solve"
227 | | )]
    | |__^ help: remove the unnecessary deprecation attribute
    |
    = note: `#[deny(useless_deprecated)]` on by default

Checks

• I have updated CHANGES.md, with [BREAKING] next to all breaking changes
• I have updated the documentation if necessary
• If 01_square example was changed, src/lib.rs and README.md were updated

[ryanisaacg]

It looks like CI is failing, may be because the CI itself is out of date.

[lenscas]

It looks like CI is failing, may be because the CI itself is out of date.

it is:

The add-path command is disabled.