Length unit

[kvid]

• This solves the basic part of [feature] Using inches and other units #7
• It is based on Adding support for wire length units #161, Add support for units to wire lengths. Part 2 #162, and add length_unit support for wire and cable lengths #171 and solves the known bugs commented in their reviews
• The commits are rebased on top of the current dev
• The bug about adding quantities of different units was fixed as part of the conflict resolution during rebasing
• The two commits by @zombielinux from Adding support for wire length units #161 and Add support for units to wire lengths. Part 2 #162 are squashed into one with authorship unchanged
• The merge commit by @stevegt disappeared during rebasing, but his real change commit is present with authorship unchanged

[formatc1702]

Thanks.
I copied it into my local pr/196 branch for squashing, to make sure authorships were preserved as expected before committing to dev.
By not using the GitHub GUI to merge, it might appear that this PR was not merged, even though the changes have made it into dev.
I hope it's not a big deal; this is an attempt at figuring out how to deal with multiple authors of one commit :-)
See the final result in dec64ab:

[kvid]

Thanks.
I copied it into my local pr/196 branch for squashing, to make sure authorships were preserved as expected before committing to dev.
By not using the GitHub GUI to merge, it might appear that this PR was not merged, even though the changes have made it into dev.
I hope it's not a big deal; this is an attempt at figuring out how to deal with multiple authors of one commit :-)

@formatc1702, Are you not able to add Co-authored-by in the GitHub GUI when preparing the common commit message for a squash merge-in?

If not, it might be an option to use the GitHub GUI to merge-in to a different branch, e.g. a new dummy length_unit3 branch to mark the PR as merged in afterwords (i.e. now)?

[formatc1702]

Good idea with the dummy branch! Thanks.

I could have done it in the GitHub GUI (just like I did now), but I wasn't sure it would work as intended, so I decided to do it locally, and didn't realize I could not just manually mark the PR as merged afterwards.

And as I just realized, when doing it via GitHub, you are marked as the main author (see 3c205fe *, will delete later); whereas I interactively rebased everything by squashing onto zombielinux' commit, making him the main author (see dec64ab), which is closer to my intention, since he kick-started this chain of PRs.

[*] I just copy&pasted the commit message from dec64ab, that's why zombielinux is missing entirely in 3c205fe

Anyway, now I know, for next time!