Add Chrome OS support for the USB Device Info app.

On Chrome OS chrome.usb.requestAccess must be called before the device
can be opened. Some adjustments to the CSS also had to be made due to
differences in the size of input elements between platforms.
Updated samples\hid to use correct hid.receive()

chrome.hid.receive() was incorrect per
https://developer.chrome.com/apps/hid#method-receive. Needs to be
changed to be functional.
Merge branch 'master' of github.com:GoogleChrome/chrome-app-samples into device-info
Use the new chrome.hid add/remove events to support multiple blink(1)s.

This change allows the user to have multiple blink(1) devices connected
to their computer. A selection box is used to switch between them. The
new chrome.hid.onDeviceAdded and chrome.hid.onDeviceRemoved events are
used to keep this list up to date.
Check for existance of HID add/remove events.

Check for whether these events are provided by Chrome before attaching
event listeners so that this code is compatible with older versions of
Chrome.
blink1: Update version number.
Merge pull request #345 from reillyeon/blink1

Use the new chrome.hid add/remove events to support multiple blink(1)s.
Merge pull request #2 from GoogleChrome/master

update