ui-macos/*: "a series of unfortunate events."

Just kidding.  This is a squash of a whole bunch of unlabeled temporary
commits that I produced over the last couple of weeks while writing a UI
for MacOS while riding on airplanes and sitting in airports.

So long, batch of useless commits!

ui-macos/bits/runpython.c

@@ -0,0 +1,14 @@
+/*
+ * This rather pointless program acts like the python interpreter, except
+ * it's intended to sit inside a MacOS .app package, so that its argv[0]
+ * will point inside the package.
+ *
+ * NSApplicationMain() looks for Info.plist using the path in argv[0], which
+ * goes wrong if your interpreter is /usr/bin/python.
+ */
+#include <Python.h>
+
+int main(int argc, char **argv)
+{
+    return Py_Main(argc, argv);
+}