This commit add an update check and webgui ajax capabilities.

1. Since the introduction of the apt pilight repository, it's easier
to track updates. This commit adds and update checker against the
pilight apt repository. To know if updates are avaiable you can check
the webgui. This commit will also communicate the current running
version and the latest upstream version when requesting the config
through the API. You can easility compare the two to notify the user
for updates.

 2. The webserver has been optimized and more instability issues
have been fixed. This commit also adds two new functions. When
calling /config page, you can see the latest config json
object. When you call the /send page you can (url encoded) send
codes as specified in the pilight API. These new pages also allow
using the AJAX interface in the webgui. This makes the webgui also
work on older (mobile) devices and browsers.
[webgui] Allow switching between tabular and vertical view

To switch, html5 storage needs to be available.
One can either press ctrl-alt-shift-t or double tap slowly.
The h key will now show all short-cuts available (currently one).
Added draft of the Clarus protocol
Fixed bug in config in which multiple protocols per device didn't always work
Let webserver respect whitelist IPs
Optimizing whitelist by caching
Integrated wiringPi external gpio program into wiringPi library
Removed wiringPi "gpio" dependency and added 1-wire dht22 sensor (thanks to @sweetpi)
Improved 1-wire sensor implementation
Added dht22 alias'