client: add support for optional tokens
optional Tokens: throw 'disableToken' when disabled

-add method buttonToggle:
  -throws disableToken/newToken
  -calls disableInputs/enableInputs
-add methods disableInputs/enableInputs which calls
this.$.input.setDisabled by default
-catch disableToken event in Main App, remove token from token array
Token: fix this.$.toggle.value initialization
add 'logo' and 'phone' options
add subject token
change address keys to more intuitive values

-addresser->from
-addressee->to