[xml] mingw configure

["Oliver Stöneberg" <oliverst online de>]

There was quite a confusion about the MinGW changes in the last 
version of libxml2.
In the 2.5.10 the configuration of the mingw win32 version has 
changed and it should be reflected/documented somewhere, that you 
can't use the configure.js anymore, but use the MSYS alternative 
shell from www.mingw.org to compile this.
And to avoid the confusion (like it caused in my case) I think, that 
"mingw" should be removed as a compiler option in the "configure.js", 
because it doesn't result in something compilable. The "configure.js" 
should be MSVC-only from now one.
It's not my decision to do that, I just wanted to point it out. Sorry 
for the confusion I caused, Daniel and Mikhail.

I also recognised, that there some redundant include paths used for 
compiling after running the configure in MSYS:

gcc -DHAVE_CONFIG_H -I. -I. -I.. -I.. -I.. -I../include -I../include -
I.    -g -O2 -Wall -c `test -f 'gjobread.c' || echo './'`gjobread.c
/bin/sh ../libtool --mode=link gcc  -g -O2 -Wall   -o gjobread.exe  
gjobread.o ../libxml2.la  -lz  -lm -lwsock32

3 times -I.
3 times -I..
and twice -I../include

seems a bit too much of including those paths.