Since 2008, autotools has served us well - thank you!
However, mu is now using meson build, and it's time to remove the
autotools support -- one build system is enough.
Some #includes were missing for the latter (but only noticeable on some
systems - e.g., build breaks on Cygwin).
So let's replace with something that works equally everywhere.
Fixes: #2060
Spec file creates the following packages:
* mu: The main email indexer, with mu4e included for emacs
* mu-gtk: with the mug executable
* mu-guile: with the bindings for guile
As per the Fedora Packaging Guidelines, there should not be a separate
emacs-mu package if the main package (mu) does not require emacs, but it
provides additional files for its use with emacs. I think that's the
point of mu4e.
Previously, the first element was used where the second should have been.
In essence, whereas the algorithm is T[0]<<16 & T[1], the code was previously performing T[0]<<16 & T[0].
The timestamp produced was therefore inaccurate by up to about 18 hours.
