Swap foreground/background when clicking current color swatches
Fix foreground/background color display for transparent color
Fix switching from transparent to another color
Add bitmap tools
Add bitmap brush icon
Add hover effect to bitmap tools
Add bitmap tool tooltips
Add bitmap line tool
Add bitmap rectangle tool icon
Fix tool background images
Add bitmap ellipse tool icon
Add bitmap text tool icon
Add bitmap fill tool icon
Add bitmap eraser tool icon
Add bitmap stamp tool icon
Fix duplicate tool hover background color
Fix bitmap tool hover colors

Closes https://github.com/nathan/pixie/issues/26.