Move ol defines from browserfeature.js to ol.js
Add missing requires

Without explicit requires, it is possible that a build would exclude ol.js.
Defines in ol namespace defined in ol.js
Defines in a namespace that can be required

For consistency, all defines are in the ol namespace.  If they are to be moved to another namespace, they need to be requireable.
Merge pull request #2030 from tschaub/defines

Move defines to ol namespace.