#16 Add clear canvas button to toolbar, confirm clear with user.

[mdhtr]

• clear button added to the right side of the right side of the toolbar
• use built-in confirm dialog to confirm clearing the canvas. dialog text was taken from index.html

[maxwellito]

Hi there,

I'm really sorry I never got notifications for your issues and PRs. Apparently, GitHub doesn't make you watch your own repos automatically.

You probably didn't notice but at the time of your PR, there were a v2 branch where a lot of new things were happening. You can not select areas, drag them, fill them, or even delete by pressing 'backspace'. If the user made a mistake, the undo button will help them.

I'm really sorry about the efforts you put into this project. I really appreciate, you did actual PRs and not just asking for features, and that's super awesome. So I will close your PRs (because they can no longer be merged now) and some issues.

Many thanks, Max