configure check for Xrandr extension

[Alex Pasadyn]

Alexandre Julliard wrote:
> My version of Xrandr doesn't need Xrender so I hoped it wouldn't be
> needed, guess I was wrong.... what does it need Xrender for?
> 
> The problem with the dependency is that currently we deliberately
> don't link to libXrender but load it dynamically so that it works on
> all platforms; so I guess we'll need to load libXrandr dynamically
> too.

Without it, I get:

> configure:7306: checking for XRRSetScreenConfigAndRate in -lXrandr
> configure:7337: gcc -o conftest -g -O2   -I/usr/X11R6/include  conftest.c -lXrandr  -L/usr/X11R6/lib -lXext -lX11  -lm  >&5
> /usr/X11R6/lib/libXrandr.so: undefined reference to `XRenderSetSubpixelOrder'
> collect2: ld returned 1 exit status
> configure:7340: $? = 1

I'm not really sure why that would be needed.  What version are you 
using?  Maybe I'm out of date?  My system is RedHat 9 and I haven't done 
anything to upgrade the XFree86 (it's all version 4.3.0).

Alex