Removed duplicate example

Removed duplicate code sample from the "Auto Plugins and plugin settings" section. This fixes issue #2996
Add migration notes about Pk deprecation (update related code samples)
Stop ClosableLazy throwing NPE when close called before get

Fixes #3024.
Merge pull request #3029 from cchantep/anorm-pkbk

Anorm Pk deprecation
Merge pull request #3030 from richdougherty/lazy-closable-npe

Stop ClosableLazy throwing NPE when close called before get
Typo: Unforseen -> Unforeseen
WsSSL exists in docs twice

Doesn't need to be in there the second time.
Merge pull request #3036 from vmunier/patch-1

Typo: Unforseen -> Unforeseen
Allow sending files with any status
Merge pull request #3042 from gmethvin/status_sendfile

Allow sending files with any status
frequency value typo
Merge pull request #3046 from sharpyfox/fix_akka_doc

Scala Documentation: Akka frequency value typo