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.
Modules used in postinstall are dependencies

Since async and htmlparser2 are used by the postinstall task, they need to be listed as dependencies.  These will get installed when ol3 is a dependency of another project.
Merge pull request #2031 from tschaub/dependencies

Move modules used in post-install task to dependencies.