Rework the build system for osx applications:

* Don't use xcodebuild for building PythonLauncher, but use a normal unix
  makefile. This makes it a lot easier to use the same build flags as for the
  rest of python (e.g. make a universal version of python launcher)
* Convert the mac makefile-s to makefile.in-s and use configure to set makefile
  variables instead of forwarding them as command-line arguments
* Add a C version of pythonw, that we you can use '#!/usr/local/bin/pythonw'
* Build IDLE.app using bundlebuilder instead of BuildApplet, that will allow
  easier modification of the bundle contents later on.

Mac/OSX/Tools/pythonw.c

@@ -0,0 +1,17 @@
+/*
+ * This wrapper program executes a python executable hidden inside an
+ * application bundle inside the Python framework. This is needed to run
+ * GUI code: some GUI API's don't work unless the program is inside an
+ * application bundle.
+ */
+#include <unistd.h>
+#include <err.h>
+
+static char Python[] = PYTHONWEXECUTABLE;
+
+int main(int argc, char **argv) {
+	argv[0] = Python;
+	execv(Python, argv);
+	err(1, "execv: %s", Python);
+	/* NOTREACHED */
+}