Use the layergroup's extent if no extent provided
Merge pull request #2960 from bartvde/layergroup-extent

LayerGroup extent should be used if extent not set on child layer
Fix pan with select interaction in mousemove mode.
Merge pull request #2965 from tonio/pan_selectinteraction

Fix pan with select interaction in mousemove mode.
Use goog.array.extend instead of ol.array.safeExtend

The upstream implementation now supports large arrays.
See https://github.com/google/closure-library/pull/356
Remove ol.Object.capitalize and use goog.string.capitalize
[wip] Update closure-compiler and closure-library