Bugfix/nls fix translation installation, closes #565 #564 #556

[01micko]

There are 2 commits here that address some recent issues:

1. a146962 addresses a minor issue with some syntax errors in po/pt_BR in the comments at the top of the file closing pt_BR translation causes error in make #564
2. 607fc3d adds AM_INIT_AUTOMAKE to configure.ac fixing a bug where @mkdir_p@ was undefined in po/Makefile causing the failure of .mo files to be installed addressing Translations not installing - automake (GNU automake) 1.16.2 #565 and Obsolete @mkdir_p@ macro in po/Makefile.in.in #556

I tested this by trying to upgrade the autotools but that failed for me, so I researched a little and found that AM_INIT_AUTOMAKE absence may have been the cause. I duely tried that and this fix works with automake-1.16.2 and automake-1.16.5, both with gettext-0.21.

Thanks @joewing for your consideration of these commits.

[01micko]

@joewing you may also want to consider this - #432 (comment)

Especially if you decide if this PR isn't warranted.

[joewing]

Thanks! I don't see any reason not to merge these.
As far as cmake is concerned... that branch is a bit out of date and I don't think handles everything. autotools are somewhat confusing, but they're everywhere and JWM already uses them so it might not be worth the effort to convert.

[01micko]

Thanks Joe 😄