[cairo] configure with pdksh fails

[Dave Yeo]

Hi, using a couple of day old git pull (trunk) configure fails here

configure[31377]: test: ==: unexpected operator/operand

when using sh from pdksh on OS/2. It does work when using bash.
Anyways all other tests use = instead of == (see tail of configure.in).
Would it be possible to change
if test x"$use_directfb" == "xyes" ; then
     echo "$WARNING_MESSAGE" | sed 's/@BACKEND@/DirectFB/'
fi
to
if test x"$use_directfb" = "xyes" ; then
     echo "$WARNING_MESSAGE" | sed 's/@BACKEND@/DirectFB/'
fi
Dave