HdyDialer: Do away with cycle buttons
There should be only one button type (HdyDialerButton) that has a property which allows it to either cycle through symbols or always use the first one since we have several different needs:
- Dialer: cycle '*+' (or '0+)
- T9 OSK: cycle everything
- Lockscreen: never cycle
Whether we should expose this as a propery on HdyDialer or make it per button configurable I'm not sure (we should at least have helpers to set the above modes).
See !112 (merged)