Merge pull request #1390 from twpayne/vector-api-misc-fixes

[vector-api] Miscellaneous vector fixes
Merge remote-tracking branch 'openlayers/master' into vector-api
Merge remote-tracking branch 'openlayers/master' into vector-api
Merge remote-tracking branch 'openlayers/master' into vector-api
Add ol.format.IGC
Add ol.source.IGC
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
Move back ol.parser.polyline
Port ol.parser.polyline to ol.format.Format
Making coding style closer to ol3's in ol.format.Polyline
Optimize encode
Add ol.format.Polyline#readProjectionFromText
Remove whitespace
Use stronger instanceof assertion
Add pixelRatio to ol.source.Image#getImage
Add pixelRatio to ol.source.Image#createImage
Add pixelRatio param to ol.Image constructor