See http://people.gnome.org/~walters/docs/build-api.txt Signed-off-by: Dave Airlie <email@example.com>
Without this the "w" flag may be set which causes the version to be incorrectly to be obtains in configure.ac causing configure to fail miserably
The defacto method to rebuild the autotools and run the generated configure is an autogen.sh script. It is much more discoverable than the custom `make configure' used here. The Makefile targets are still useful for creating tarballs, though. This autogen.sh is copied from Xorg.