wxWidgets: add patches to support KiCad

[mojca (Mojca Miklavec)]

KiCad (#47268) requires some patches of wxWidgets. Here's a list of ​patches for wxWidgets from the KiCad's ​build instructions:

in master

• ​wxwidgets-3.0.0_macosx_scrolledwindow.patch (include; also in 3.0 branch)
  • some scrolling events
• ​wxwidgets-3.0.2_macosx_magnify_event.patch (include; not in 3.0 branch)
  • adds support for a magnifying mouse gesture (possibly compare the patch with master)

not in master

• ​wxpython-3.0.0_macosx_multiarch.patch
  • handles arch flags in build scripts, most likely not needed
• ​wxwidgets-3.0.0_macosx.patch
  • it replaces carbon with cocoa at some places and fixes overlays (I don't completely understand it)
  • the patch for wxPython is slightly different from the patch for wxWidgets
• ​wxwidgets-3.0.0_macosx_bug_15908.patch
  • some dirty patch to avoid crashes (I don't understand it, not sure what to do)
  • see also ​http://trac.wxwidgets.org/ticket/15908
• ​wxwidgets-3.0.0_macosx_soname.patch
  • it avoids running change-install-names, needs further inspection (perhaps neither needed nor harmful)
  • see also ​http://trac.wxwidgets.org/ticket/15452

• ​wxwidgets-3.0.2_macosx_data_view_ctrl.patch
  • I don't understand it
• ​wxwidgets-3.0.2_macosx_retina_opengl.patch
  • see also ​https://forums.wxwidgets.org/viewtopic.php?t=36684
  • see also ​https://wiki.wxwidgets.org/WxMac-specific_topics#Retina_display_support
• ​wxwidgets-3.0.2_macosx_yosemite.patch
  • why exactly is this needed and not included upstream?

And here's an ​alternative link with patches and build scripts.