#61 AC_CONFIG_SRCDIR with ADD_EXTRA_DIST()

[Joerg Faschingbauer]

If Confix2.pkg and Confix2.dir are the only package members, then one of them is the argument to AC_CONFIG_SRCDIR() in the generated configure.ac file.

If the are nontrivial files contained in the package, then one of these is chosen.

The bug is: one of these is only chosen when there is a builder object that handles them. If the only nontrivial file is added to the package using ADD_EXTRA_DIST(), then the file is ignored.

Solution:
* add a test tolibconfix/plugins/automake/tests/ac_config_srcdir_suite.py
* modify ADD_EXTRA_DIST() to wrap a builder around the file (this is more natural anyway)