Don't just create a .PHONY target which runs a script that magically
generates files ninja doesn't know about. It results in untracked files,
and `meson install` has to run additional commands instead of copying
over files, and then cannot track them to uninstall them later.
I'm not even really sure why it was originally done via a proxy script,
most likely bad legacy design. This is after all one of the oldest
modules...
One side effect of this is that meson doesn't know how to rename
build.CustomTarget files on install (only data files are supported?),
and every file needs to be installed as "domainname.mo" so it must be
named that in-tree too. To prevent clashes, every locale gets its own
locale-specific subdirectory.
Once we are doing that anyway, we can output them to the actual
structure required by the gettext family of functions, and
bindtextdomain() can therefore point to this location if desired. This
might be useful for running localized programs from the build tree.
487d45c1e5