Use toString() instead of + ''
Move proj.exports and proj.jsdoc into proj directory
Move layer.jsdoc into src/ol/layer
Add missing dependency for build/ol-all.js
Sort externs files alphabetically
Merge pull request #1453 from twpayne/clean-ups

Miscellaneous clean-ups
Fix issue with valueExtent_ being cleared while updating extents, but never being repopulated
Merge pull request #1458 from Intermedix/bug-insert-valueExtent

Fix bug in ol.structs.RBush#update
Add a ol.source.ImageStatic example
Merge pull request #1374 from fredj/static-image-example

Add a ol.source.ImageStatic example