Do not export the ol.render.canvas.Immediate constructor
Use native JSON.parse function
Remove undocumented symbols at the end of the parsing process

This ensures that we do not mark symbols as undocumented before
all potential dependencies are parsed.
Only add symbols to the unexported array once

This basically fixes a typo that caused unexported symbols to
be added to the unexported array multiple times.
Also consider linked symbols as documented
Make ol.render.canvas.Immediate available in the docs
Make ol.View2D available when exploring olx.MapOptions
Merge pull request #1901 from ahocevar/canvasimmediate-less-exports

Do not export the ol.render.canvas.Immediate constructor
Do not query the array twice
Merge pull request #1904 from ahocevar/doc-improvements

API doc improvements
Merge pull request #1902 from fredj/native-json

Use native JSON.parse function
Rename ol.source.VectorFile to ol.source.StaticVector
Factor out ol.source.FormatVector
Rename ol.source.FormatVector#loadFeatures to loadFeaturesFromURL
Load features before rendering
Add ol.loading
Add ol.source.RemoteVector
Load features on demand in vector-osm example
Export ol.format.OSMXML
Add projection argument when loading features