wxWidgets 2.6.3

 (this is a workaround, i'm too lazy to find where they double up the LDFLAGS when they link their applications).

- added libunicows in contribs for win32 builds to support Microsoft Layer for Unicode on Win95/98/ME (http://libunicows.sourceforge.net/)

all: for Cygwin, make sure that the program-prefix is empty, so that libgcrypt-config & gnutls-config are not prefixed by the target build (i586-mingw32msvc), which causes prevents configures scripts from detecting them

extras/contrib/src/Makefile: cleaned up INSTALL_NAME macro for MacOS X: all the dylib in contrib/lib are soft-linked to their distributed version in 'vlc-lib'. this way, VLC build system can use contrib libs on MacOS X the same way as for UNIX, and should simplify porting to libtool
configure.ac: cleaned up Cocoa.h detection, removed link path dependency to 'vlc-lib' as it is no longer necessary
Makefile.am: fixed installation of dylibs as vlc_ prefix is already appended by INSTALL_NAME

NOTE: this change is highly disruptive for MacOS X build, I strongly recommend that you rebuild the contrib packages for this platform. Other platforms are unaffected