* introduce pako and add general packer interface
* add tests for packer
* use function API instead of class API for better tree shaking support
* refcatoring the rollup bundle config
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
