Add ol.format.IGC
Add ol.source.IGC
Remove View2D typecasts in bind-input example
Remove View2D typecasts in geolocation example
Make Interaction inherit from Observable
Merge pull request #1397 from elemoine/observable

Make Interaction inherit from Observable
Merge pull request #1396 from elemoine/typecasts

Remove typecasts in examples
Add IGC example
Remove complex-geometry example
Merge pull request #1360 from twpayne/vector-api-igc

[vector-api] ol.format.IGC
Merge remote-tracking branch 'openlayers/master' into vector-api
Add pixelRatio to ol.source.Image#getImage
Add pixelRatio to ol.source.Image#createImage
Add pixelRatio param to ol.Image constructor
Use the image pixelRatio in ol.renderer.canvas.ImageLayer
Add hidpi option to ol.source.ImageWMS and ol.source.MapGuide