Add WithApplicationLoader specs2 scope
Added more Http Headers & fixed ETag header
add Json#parse(input: InputStream)
Swap first AkkaHttpServerSpec test and increase timeout

The first test in AkkaHttpServerSpec has been failing in master. The
purpose of this change is to investigate why. Is it only the first
test that fails? Is the failure something to do with the slow CI test
box? Once we've worked out the solution, we should be able to revert
this change.
changed play -> activator in ProductionDist

Some examples still listed "play" as the command to execute, I changed it to activator.
Refactored based on PR comments, and made encoding/decoding more efficient
Add notes about migrating to older versions of Play for Crypto APIs