This option is going to be mandatory starting with automake 2.0.
LyX is able to use this since version 2.1, but it turns out that it is
badly implemented in versions of automake older than 1.14.
We rely on some (undocumented) symbol to detect automake 1.14 and
use the subdirs-objects option in this case.
For more details, see:
https://www.mail-archive.com/lyx-devel@lists.lyx.org/msg181023.html
Making everything work with autotools required making a copy of two
files from support/tests. It seems that we should not point to source files
that are handled by another Makefile.am.
Since 00387b2a38 it is possible to construct a dummy Messages object
which does not translate at all. With the old gettext implementation, a
Messages object without a defined language would have used a language from
an environment variable. Therefore, the duplicate definition of _() is no
longer needed. This gettext removal was really a good idea!
1.) Do not include layout tests on MAC, since the
linker-option which allows multiple definitions is
no longer supported.
2.) Indenting made consistent
