Update ebean doc
update typesafe config 1.2.1

akka 2.3.3 depends on typesafe config 1.2.1 https://github.com/akka/akka/blob/v2.3.3/project/AkkaBuild.scala#L1146
I think we should use same version
Lazily load SecurityHeadersConfig
Merge pull request #2974 from gmethvin/security_headers

Lazily load SecurityHeadersConfig
Fix ScalaDependencyInjection.md's Spring description grammar
Update SBT Cookbook documentation.

The SBT Cookbook contained a reference to the playAssetsDirectories
attribute that was removed in play 2.3.
Added details of how to import the cache into the documentation
Merge pull request #2990 from Lykathia/documentation-update

[doc] Update SBT Cookbook documentation.
Merge pull request #2982 from leeduan/master

Fix ScalaDependencyInjection.md's Spring description grammar
Fix the link to the auth scheme to be WSAuthScheme
Fix link to sbt
Merge pull request #2972 from xuwei-k/update-typesafe-config

update typesafe config 1.2.1
Merge pull request #2956 from cchantep/fix-2956

Where to put libraryDependencies += javaEbean ?
remove akka version
Merge pull request #2995 from yanns/doc-remove-akka-version

remove akka version