Add option to specify element to focus on canvas click.

Merge pull request #7 from trinketapp/feat/different-focus-element

another attempt to fix the focus problem

key event filtering

Merge pull request #5 from trinketapp/key-events

add event filtering

setup first, setup error propagation

Merge pull request #4 from trinketapp/feat/async-draw-and-setup

dont restart the loop on framerate from setup and call onsetup callback with error

double buffering

Merge pull request #3 from trinketapp/feat/async-draw-and-setup

add double buffering

error callback

Merge pull request #2 from trinketapp/feat/async-draw-and-setup

Feat/async draw and setup

async setup and draw capabilities

Merge pull request #1 from trinketapp/feat/async-draw-and-setup

Feat/async draw and setup