Lock offline template cache to a particular index hash

This gives us the ability to rebuild old versions of
activator. It means that for example our CI won't start
to fail as soon as someone updates one of the featured
templates.

Initially locking to the hash that shipped with
Activator 1.2.3
Fixed log message from java version check that said local when it wasn't
On publish and S3 upload, complain about outdated cache hash
Move the check for latest hash to after publishSigned

Apparently the before-publish hooks I was using are needed
for offlineTests and integrationTests too.
If /activator/latest returns non-200, don't use the version info
Merge pull request #607 from typesafehub/wip/havocp-lock-template-cache

Lock down the template index version
Merge pull request #609 from typesafehub/wip/havocp-handle-failed-latest

If /activator/latest returns non-200, don't use the version info
Bump versions for Play 2.3.2; offlineTests not working

 Play to 2.3.2
 sbt-remote-control to 1.0-8756df5dedb13e490ab9ce8a11dbb5a0b5c02362
 sbt-echo to 0.1.1.3 (which appears to be newer than 0.1.3 - not sure
   what happened there)
 Added another junit version, plus some explicit plexus and jsch deps.
 Do not understand why any of these were suddenly necessary.

In this commit things are broken; it seems that jsch never gets
downloaded and is not in local-repository after the local-repository-created
task. Then the offlineTests can't find it.

Some of the offlineTests failures are just because templates haven't
been updated to latest Play, but play-scala and play-java are somehow
failing on this jsch thing.
Use 2.11-based sbt for sbt-remote-control and activator-template-cache and ourselves
Bump to template cache hash 06a31bb927e0a5e8fbf9f5f08dce4abc2f5f23b2

This is the latest cache as of this timestamp