Fix cmake install

[20162026]

fix #80 and maybe #92 (yet to test CE locally)

[wusatosi]

Let me invite our CMake genius. @nickelpro

btw @20162026 I might be inactive for about one to two weeks, I have an interview coming up so I won't have much time to focus on beman. Review might take longer :|

[nickelpro]

The option() docstrings should get fixed, other comments are stylistic and not blocking.

Approved on the basis that everything is mechanically correct, but please fix docstrings prior to merge.

[wusatosi]

Feel free to merge once requested changes by @nickelpro is implemented, I just gave @20162026 write access to this repo.

[wusatosi]

I don't think there's any way to test if #92 is fixed locally... @neatudarius do you know anything about testing compiler explorer locally

[20162026]

I don't think there's any way to test if #92 is fixed locally... @neatudarius do you know anything about testing compiler explorer locally

It should be testable and reproducible locally (at least compilers are), but in the worst case, I'll just check again after this PR is merged and CE updates deps.

[wusatosi]

in the worst case, I'll just check again after this PR is merged and CE updates deps.

I am fine with this, setting up compiler explorer maybe a pain.

[nickelpro]

LGTM