Add Tests

[dethe]

Add automatic tests for the following (at least):

• esc to toggle UI
• d to toggle display
• ctrl-z for undo
• ctrl-y for redo
• n for new animation
• ctrl-s to save
• ctrl-o to open a file
• g save as gif
• p save as png
• shift-1 pen
• shift-2 rotate
• shift-3 move
• shift-4 zoom in
• shift-5 zoom out
• shift-6 eraser
• shift-+ increase pen/eraser size
• shift-- decrease pen/eraser size
• 1-8 colors 1-8
• shift-n add frame
• shift-delete remove frame
• shift-c clone frame
• shift-x clear frame
• shift-leftarrow first frame
• leftarrow prev frame
• right arrow next frame
• shift-rightarrow last frame
• k toggle onionskin
• r play animation
• Click palette to toggle UI
• Show About
• Show shortcuts
• Toggle file, draw, frames, animate ribbons
• New button
• Load button
• Save button
• GIF button
• PNG button
• Switch between all tools with menu
• Change pen size
• Pen/eraser size should not go below 1
• Palette changes from menu
• Change colour
• Change background colour
• Choose from quick colours
• Set quick colours
• Add frame button
• Remove frame button
• Copy frame button
• Clear frame
• First/back/next/last buttons
• Onionskin toggles with checkbox
• Play button works
• FPS takes effect
• bgcolor maintained after playing animation
• All custom settings, including colours, saved and restored in page reload
• All custom settings, including colours, saved in SVG and restored on load