* refactoring play, pause, resume, load style sheet to subscribe style code
* support live mode in state machine
* 1. upgrade @xstate/fsm
2. add toggle interact methods to the player
1. add a liveMode flag to config, when liveMode is set, the timer
will keep running even though all the actions casted
2. add a public method addEvent, which will cast newly added event
in sync
3. move mouse in sync mode with the latest position info
Skip inactive time is an important and useful feature. We consider
user interaction events as active, and check next user interaction
event after apply incremental snapshot.
If next user interaction event has a time gap larger than the
threshold, we will set a dynamic speed value which will skip the
inactive time interval in about 5 seconds.
Before this patch, the checker in the timer will stop only when
actions array is empty.
When we call play more than once, it will clear the timer first,
then push filtered new actions and start the timer again. If
all of this happened in a frame, the checker which should be
cleared may found actions array is not empty and keep check.
So this patch we use timer.raf to hold raf's handle and cancel
it when clear was called.
