Authenticate users to Twitter in order to accept API calls

[frankleonrose]

Twitter is just the default OAuth provider we'll start with. We can add others later.

• Authenticate on client
• Store auth parameters for reuse
• When logged in, show current login status in Account view
• Re-authenticate when auth parameters have expired
• Send auth parameters in request header
• Encourage the user to log in if they have not. Show a dismissable panel with a button to go directly to login.
• Send non-tracked Lora packets when no history of logging in