ui: Add QR code for configuring mobile clients.

Creates new page @ /ui/mobile.html for generating a QR code that
embeds configuration data for setting up mobile clients.

Imports code.google.com/p/rsc/{gf256,qr} version:

parent: 149:a3cbaf2339c4 tip

This addresses the server and web components of
https://camlistore.org/issue/372

Change-Id: If9239dd138707080afd7dedb5770d04893cbf0ba
Merge "ui: Add QR code for configuring mobile clients."
tests: make sure camlistored is running before cammount

Context: http://camlistore.org/issue/385

Change-Id: I793298745096fc1696f01226698eb6682b24806d
tests: ping camlistored before camput

Change-Id: Icf66bd5b990db07e9516b8ab8945cbf681caf25e
camput: fix camput blob from stdin

Change-Id: Ic9997c408e1241e16dd4470b3f733ef3fb4f79c9