hooked up settings state for play notifications

users can now specifiy whether or not notifications will play; preserved
in localStorage across browser sessions
removing cruft; adding button thumbnail state

no real state management on the buttons; simply remove the '-selected'
string from the src property of all nav menu images; then add
'-selected' to the nav button being clicked
setting BNetClient as singleton; changing page init

using the jQuery document ready handler to kick of the initialization
process. This may be un-necessary, given how small the background page
is, but is insurance that things will be ready before the javascript
objects start being constructed
adding dev mode behavior to simulate new entries

getNewsMock will now generate 3 new news items per iteration with
slightly incremented time stamps. This is to trigger the 'new item'
notification behavior while testing.
turning off dev mode and removing a function

the function is never called