firstMatching -> firstWhere
Timer.repeating -> Timer.periodic
API updates

firstMatching -> firstWhere
new drawImageAtScale
importing Rect from dart:html
added default positions for layer controls
added SimpleZoomControl, improved control layouts

Various small changes
updated README
version 0.0.4
firefox specific mouse wheel
switching to screen coordinates

Generated javascript in Chrome: offsetX always equal to offsetY
version increment
Merge branch 'work'