Add patch number to version

[brson]

Yet another issue that I am sure existed at one point but that GitHub will not help me find. Rust currently only uses major.minor version numbers, but semver calls for major.minor.patch. Nominating.

[bstrie]

Child bug of #11396

[pnkfelix]

Accepted for 1.0, P-backcompat-libs.

[emberian]

I can take this.

[kaseyc]

The lack of the patch version is interfering with implementing #3795, due to the current version numbers not being accepted by Rust's semver implementation. It's a minor issue all things considered, but it would be nice to have it changed sooner rather than later.