bootstrap: test for the presence of contrib/share/aclocal before including it because m4 react badly to missing directory

 * skins2/src/theme_loader.cpp: Fixed another directory delimiter issue. The winamp skins load perfectly on windows now...

* winamp2.xml: more controls

* theme_loader.cpp: correct handling of subdirectories in winamp
  skins

 lot of things to do but it works !
* theme_loader.cpp: when a theme contains no XML file, assume
 we are trying to load a winamp skin, and use winamp2.xml
* vlcproc.cpp: repaired text variables ($N was broken)

  several bitmaps in a skin from regions of the same image file.
  Usage is:
  <Bitmap id="body" file="main.bmp" alphacolor="#FF0000">
    <SubBitmap id="sub1" x="0" y="10" width="100" height="100" />
    <SubBitmap id="sub2" x="100" y="10" width="100" height="100" />
  </Bitmap>

  Borrowed code from Gilles Vollant for the unzip part
  (I guess this code should be put elsewhere in vlc, but it was
  the easy way for me at the moment;) I hope it compiles fine
  everywhere, I've tested only on linux.
  Now, everything's ready for winamp skins ;)

 can be loaded

 taken into account, which caused getting RGBA pictures instead of ARGB,
 or GBR instead of RGB). 8bpp is obviously broken too, I have not tested it.
 --> now BMP images (and other formats) can be used in skins, not only PNG!
  (of course the goal is to add a winamp skins loader ;-)

 "equalizer.enable()" and "equalizer.disable()" to enable
  or disable the equalizer audio filter.
  + small fixes

Bug report credited to Matthew Hodgson

* modules/codec/libmpeg2.c: use sequence->picture_width insted of display_width since display_width is used to convey the pan&scan info.

* ALL: changed VOUT_SET_ZOOM into VOUT_SET_SIZE and implemented a VOUT_GET_SIZE for some of the vouts.

  It can be defined in the XML with usual sliders, using the new
  variables equalizer.band(0), ..., equalizer.band(9)
  (0% means -20dB, and 100% means +20 dB).
  More things to come, but it is already working as is.
* all: AsyncQueue::push() now does also a remove() by default, as
  the two methods are always called together

* extras/contrib/src/Makefile, extras/contrib/src/Patches/libmpcdec.patch: patch for libmpcdec on win32.

* extras/contrib/src/Makefile: disable asm in FLAC on win32 since its build system insists on creating elf objects (would need fixing).