xine-lib jack audio output plugin still uses deprecated jack_client_new()
function. This function has been superseded by jack_client_open(). New API
has an advantage that jackd is allowed to alter name of the client in case
of ambiguity.

Using bitmeter, I found that xine's jack output suffers from the problem
mentioned at the bottom of bitmeter's home page.

"Although JACK itself works entirely with IEEE floating point values the
 conversion to and from analog audio uses integers, as do popular audio
 storage technologies like DAT and Red Book CDs. For correct operation JACK
 software which uses such integers should use the same conversion ratios as
 JACK itself. e.g. 16-bit samples should be divided by exactly 32768.

 A common mistake is to choose the value 32767 instead. You can't hear this,
 or see it with ordinary meters, but the bitmeter shows a clear signature for
 audio processed in this way. The 8th bit of the mantissa (counting the
 rightmost as the 0th) is orange, indicating that an unusually high
 percentage of samples have this bit set."

 (from http://users.ecs.soton.ac.uk/njl98r/code/audio/bitmeter/
  via Google cache)

At the moment playing multichannel audio via the sndio backend results in
garbled sound. This disables the multichannel audio support until I have
more time to look into a better and more appropriate fix.

This requires that many other files include config.h themselves.
Also convert <config.h> to "config.h".

Update for build with newer mingw compilation tools.

It was not possible to compile some parts of XINE-LIB with NLS enabled. It's
also a good idea to explicitely enable --enable-stdcall-fixup for solving a
huge amount of warnings. Attached patch fixes these problems.