Re-enabled i420_yuy2_mmx on Darwin/x86.

- FromLocaleDup() returns a string to be freed with free() instead of LocaleFree()

 nor pkg-config

with proper configure checks

(ie. most) automake users are used to.
If you DO want NOT to use maintainer mode you are free to pass
--disable-maintainer-mode to configure.

    OS X x86, because it's just an undefined function; so we use the keyword
    "vector" to make sure.

	      Still got to find a cleaner way to determine if we have Xv.so or Xv_pic, ...

    the reserved words CXXFLAGS and LDFLAGS.
  * configure.ac: remove spaces inside parentheses that confuse automake.
  * Makefile.am: do not use both = and += inside conditionals.

(if only we had a cleaner UPnP stack)

  this and [13857] [13858] refs #182

* realigning of some of the configure --help options
* added --with-macosx-sdk
  - compiles VLC (not contrib) with the 10.3.9 SDK
  - uses a small hack to enforce the deployment target when you do make in the srcdir
  - requires you to use gcc 4.0 on on Mac OS X 10.4

Add a DirectFB module. Patch by: Iuri Diniz <iuri_at_digizap_dot_com_dot_br> applied with some coding style cleanup and autoconf fixes.