plugins: transform canPlay() in static method (refs #41)
playback handler: change src to sources (refs #39)
add a base plugin type
container: closes #43
container: improve mixin feature to enable chaining (refs #43)
container: add test for 'with' method
stats: use plugin base object
poster: fix the search of poster source to a generic way
components: add dumb loader (refs #38)
use Loader component to load external plugins (refs #38)

Conflicts:
	src/components/core/core.js
README: update the way that player handle sources (closes #39)
media control: hide controls faster
pip plugin: change files to new-style plugins (refs #7)
watermark: fix image size (refs #9)

Conflicts:
	src/plugins/watermark/public/watermark.png
add dumb global plugins handler (closes #42)

Conflicts:
	src/components/core/core.js
utils: add super method implementation to call methods from "superclass"
Conflicts:
	src/base/utils.js
playback handler: change to use plugin loader
loader: add chromecast support
container: add hover event (closes #45)
pip: listen to hover to mute/unmute container volumes (refs #7)