Merge master.

diff --cc wscript
index 5414f13d2b115b3a972d7270502d37977603fa14,1a64812a1ffea9e9704c8ef0e38488733ca37a23..004be672f772fd8baa993ad973bc148c647d6ae1
--- 1/wscript
--- 2/wscript
+++ b/wscript
@@@ -7,8 -7,10 +7,9 @@@ VERSION = '0.53pre
  def options(opt):
      opt.load('compiler_cxx')
      opt.add_option('--target-windows', action='store_true', default = False, help = 'set up to do a cross-compile to Windows')
+     opt.add_option('--osx', action='store_true', default = False, help = 'set up to build on OS X')
      opt.add_option('--enable-debug', action='store_true', default = False, help = 'build with debugging information and without optimisation')
 -    opt.add_option('--static-openjpeg', action='store_true', default = False, help = 'link statically to openjpeg')
 -    opt.add_option('--static-libdcp', action='store_true', default = False, help = 'build libdcp and in-tree dependencies statically')
 +    opt.add_option('--static', action='store_true', default = False, help = 'build libdcp and in-tree dependencies statically, and link statically to openjpeg and cxml')
  
  def configure(conf):
      conf.load('compiler_cxx')
@@@ -16,7 -18,9 +17,8 @@@
      conf.env.append_value('CXXFLAGS', ['-DLIBDCP_VERSION="%s"' % VERSION])
  
      conf.env.TARGET_WINDOWS = conf.options.target_windows
 -    conf.env.STATIC_OPENJPEG = conf.options.static_openjpeg
 -    conf.env.STATIC_LIBDCP = conf.options.static_libdcp
 +    conf.env.STATIC = conf.options.static
+     conf.env.OSX = conf.options.osx
      conf.env.ENABLE_DEBUG = conf.options.enable_debug
  
      if conf.options.target_windows:
@@@ -24,9 -28,13 +26,12 @@@
      else:
          conf.env.append_value('CXXFLAGS', '-DLIBDCP_POSIX')
  
+     if not conf.options.osx:
+         conf.env.append_value('CXXFLAGS', ['-Wno-unused-result'])
+ 
      conf.check_cfg(package = 'openssl', args = '--cflags --libs', uselib_store = 'OPENSSL', mandatory = True)
      conf.check_cfg(package = 'libxml++-2.6', args = '--cflags --libs', uselib_store = 'LIBXML++', mandatory = True)
 -    if conf.options.static_openjpeg:
 -
 +    if conf.options.static:
          conf.check_cc(fragment = """
                         #include <stdio.h>\n
                         #include <openjpeg.h>\n