Gaetan Nadon authored Mar 17, 2011 and Keith Packard committed Mar 18, 2011

A handful of modules have begun adding unit test programs.
These macros will help providing a consistent interface which will
help package builders and developers to manage the functionality.

XORG_ENABLE_UNIT_TESTS will turn on/off unit testing, regardless
of how it is implemented. The default (yes/no) can be specified by each
module. It can be used by itself if glib or -wrap support is not needed.

XORG_WITH_GLIB will probe the system for glib-2.0. A different version
can be specified in each module. It will consult XORG_ENABLE_UNIT_TESTS
but can be used by itself in contexts other then unit testing.
The default (yes/no) can be specified by each module.

XORG_LD_WRAP will probe the linker for -wrap support. It will consult
XORG_ENABLE_UNIT_TESTS but can be used by itself in contexts
other then unit testing.

configure options:
  --enable-unit-tests     Enable building unit test cases (default: auto)
  --with-glib             Use GLib library for unit testing (default: auto)

Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Gaetan Nadon <memsize@videotron.ca>
Signed-off-by: Keith Packard <keithp@keithp.com>