Expand transition syntax

Add ability to define multiple transitions in a single line (when transition config / event name is shared)
Add ability to define a second transition with the same event name and both work (when transition config is not shared)

Added in StateMapping as a wrapper for the hash used to represent a state map.
Because of this, was thinking it would be nice if a Transition object only stored its configuration. There's no need to store the end_state.