Small adjustment to autogen.sh and documentation for macOS compilation

[Marcool04]

Hi there, Having attempted successfully to adapt the autogen.sh script to macOS, I thought I'd try and provide a working pull request that would allow anybody to do the same. I understand of course if you'd rather not include this, for example if you can't test it yourself and prefer to publish only tested material. Thanks for a really handy little program! Regards, Mark.

[pentix]

Hi Mark

Thank you very much for providing this pull request! I'm very happy it seems so handy for you that you decided to update the build system to make it available on macOS!

I will absolutely include this :) Another PR (#41) recently ported it to Windows, and there were some changes on both, the build system as well as continuous integration, so I'll likely integrate both at the same time, as soon as I find some time.

(For my reference, here's some stuff that I want me to remember:)

• [x] #41 hasn't made its way to master yet, make sure building the project works fine on all 3 platforms after merging
• [x] Try to update Travis CI to build it on macOS too, maybe including artifact uploads?

Thanks again, and happy journaling! :)

[Marcool04]

No problem. Clearly quite a bit more work went into the Windows PR than this one 😉. Glad you're pleased with it. Thanks again for your work. Regards, Mark.

[pentix]

Merry Christmas and thanks again @Marcool04, the instructions should be complete now! :)

[Marcool04]

Hey thanks, a very merry Christmas to you too! All the best, Mark.