Fix condition that always evaluated to False.
Include tests in "make dist" tarball

...even for out-of-tree builds.
Declare forgotten source files in Makefiles.
Kill conf.h, with fervor

... and rename it to config.h which is the standard. Most 3rd
party files we include already used the latter and we had to adopt
them -- not any more.
Use #include <config.h> consistently instead of "config.h"

...since config.h is always in our -I paths.
Merge branch 'master' into bug2214
Add missing newline at EOF.
Set proper permissions for acceptance tests in "make dist" tarball.
Fix segfault when fopen() fails.
Include tests/unit/data/ recursively in dist tarball.

The previous EXTRA_DIST wildcard hack didn't work as expected so
for now just include the whole subtree.
Merge pull request #381 from jimis/bug2214

Bug2214