LIBVIRT_ARG_WITH_ALT is more generic than LIBVIRT_ARG_WITH, which
is tailored at switching features on and off.
Rename the macros according to their intended purpose, and add
some documentation to help developers pick between the two.
Usage of AC_REQUIRE will mess with order how LIBVIRT_CHECK_* macros
are composed into configure.ac. This ensures that the output of
configure --help is properly ordered and grouped into sections.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Following patch will update LIBVIRT_CHECK_(LIB|LIB_ALT|PKG) macros in
a way that you will be able to call a another macro as a fallback if
the first one fails. To allow that, we need to move the
LIBVIRT_ARG_WITH out of those macro to not have two or more same lines
in output of "configure --help".
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>