Ignore automatically generated files by autoconf and automake

[fel1x-developer]

With change, developers can use newer versions of Autotools when it is not updated on FreeBSD ports. Internal changes in Makefile.in, m4/, etc will be ignored when ./autogen.sh and ./configure

[bapt]

I actually plan to remove entirely autotools, (not fully decided yet) so I will take time to think about it more before merging this

[bdrewery]

build-aux/test-driver shouldn't be removed as it has customizations for the test framework. I don't like the route here. Poudriere is supposed to be self-sufficient but this creates a dependency for no benefit. As for switching away from autotools I don't see the point there either. What we have works and the test framework is integrated into it.

[fel1x-developer]

I don't like the route here. Poudriere is supposed to be self-sufficient but this creates a dependency for no benefit. As for switching away from autotools I don't see the point there either. What we have works and the test framework is integrated into it.

As autoconf and automake are already required, I don't think many users will be bothered by this change. libtool is a part of autotools (and also devel/autotools metaport), and autoconf-archive is also accessible to FreeBSD users with pkg or ports.

The benefit of this way is that we no longer need to update test-drivers/ and m4/ from the upstream autoconf-archive manually. Also, I don't think it's a good practice to keep automaticallly generated file under version control.

StackOverflow thread about this topic

[fel1x-developer]

Since test-driver is customized for our own use, I agree that it should be tracked under version control.

[fel1x-developer]

Fix merge conflict