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/askpass.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python
+import sys, os, re, subprocess
+
+prompt = ' '.join(sys.argv[1:2]).replace('"', "'")
+
+if 'yes/no' in prompt:
+    print "yes"
+    sys.exit(0)
+
+script="""
+	tell application "Finder"
+		activate
+		display dialog "%s" \
+			with title "Sshuttle SSH Connection" \
+			default answer "" \
+			with icon caution \
+			with hidden answer
+	end tell
+""" % prompt
+
+p = subprocess.Popen(['osascript', '-e', script], stdout=subprocess.PIPE)
+out = p.stdout.read()
+rv = p.wait()
+if rv:
+    # if they press the cancel button, it returns nonzero
+    sys.exit(1)
+g = re.match("text returned:(.*), button returned:.*", out)
+if not g:
+    sys.exit(2)
+print g.group(1)
+