Split the tag handling in PlayerApp into two parts: The low level
handling of changed/removed tags from the Nfc reader, including the
timeout processing is moved into the nested TagStateMachine class. The
main PlayerApp has two new (internal) callbacks "onNewTag" and
"onTagRemoved" which are called when a new tag is presented or a tag was
actually removed. This will hopefully make the implementation of #28
"Configurable Tag Handling" cleaner.
Signed-off-by: Matthias Blankertz <matthias@blankertz.org>
Matthias Blankertz
b5e3df1054