build: switch to strict POSIX makefile

[svmhdvn]

Requesting feedback on the following conventions:

• <OPTIONAL FLAG> = [Y/N] vs <OPTIONAL FLAG> = [1/0]
• READLINE vs ISOCLINE by default (I believe it should be ISOCLINE to keep dependencies simpler)
• TODO

[infradig]

I think on BSD systems (including MacOS) ISOCLINE should be the default.

[infradig]

Maybe EDITLINE could be used and get rid of ISOCLINE source and readline dependancy. Probably a big job though, a project for someone willing.

[infradig]

Hi, is still active?

[svmhdvn]

Yes please consider it active. I haven't gotten around to finishing it yet, but it's almost done locally. Sorry about that!

[jgarte]

@svmhdvn Hi, what's the status on this PR?

[lemenkov]

Maybe better switch to something modern? Meson or maybe CMake? I have a working Meson prototype already.

[infradig]

Maybe better switch to something modern? Meson or maybe CMake? I have a working Meson prototype already.

Appreciate the thought and I have used all those tools, but a definitional requirement is plain old C using a plain old Makefile.

[svmhdvn]

I agree. I also do like meson and ninja for new projects, but for the goals of this one, plain POSIX Makefile seems perfect.

And sorry for the delay once again, I still have this WIP in my tree, I've been postponing it a bit, I'll get it done soon.