Give precedence to feature style
Distinct style function types
Add option to process GPX extensions nodes

Fixes #1791.
Add tests for GPX extensions
Automatically dispose the ViewportSizeMonitor
Dispose the tiles removed from the cache
Rename ol3Logo to logo in map options
Reuse event pixel to compute the coordinate
Merge pull request #2429 from fredj/reuse-pixel-for-coord

Reuse event pixel to compute the coordinate
Update introduction tutorial
Update to use the correct default style function namespace
Test to make sure that feature styles take prececence
Allow string & object to be passed as map logo
Uncollapse when there’s only logos
Fixes wording in comments
Set type=button to avoid forms submit
Add link support for source logos
Wording in docs
More complete doc for `logo` option
Type check with `olx.LogoOptions`