Remove package objects from models and controllers

These files are used for documentation only. Useful, but prohibit me
from adding package objects with real logic in my project.
Merge branch 'master' into remove-package-objects
Remove package objects from models and controllers

These files are used for documentation only. Useful, but prohibit me
from adding package objects with real logic in my project.
for ticket 801, must explicitly enable Down evolutions with -DapplyDownEvolutions.db=true
Replaced placeholder resource file with a Scala dummy object
Replaced placeholder resource file with a Scala dummy object
Removed MissingFilePart
add requireJsFolder, requireJsShim config key
Quoted filename in content disposition header
Support application/xml, and prefer it over text/xml
Add Enumeratee.flatten
Update documentation/manual/scalaGuide/advanced/iteratees/Iteratees.md

Changed from Promise to scala Future fixed issues with codes.
Update documentation/manual/scalaGuide/advanced/iteratees/Iteratees.md

Minor: Comment added.
Update documentation/manual/scalaGuide/advanced/iteratees/Enumeratees.md

Fixing typos and changes for scala futures. Made sure that code compiles and run.
[#921] Ensured WS closes the stream when iteratee is done early
Security.Authenticated returns EssentialAction instead of Action[(Action[A], A)]
Introduce EssentialAction in the documentation
Documentation. correct JsPath method name: reads -> read.
Support H2 database options in play.api.test.Helpers.inMemoryDatabase
Minor cleaning in json lib
  - Remove duplicated code between `JsPath` companion object and class
  - Make `__` an alias of `JsPath`