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On publish and S3 upload, complain about outdated cache hash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
Fix stale template cache information

 * if the cache already existed, we didn't re-download when
   we changed the hash
 * IO.download was downloading a stale current.properties
   which it apparently cached someplace
Merge pull request #611 from typesafehub/wip/havocp-stale-cache

Fix stale template cache information
Include localTemplateCacheHash info in README

Release instructions now require understanding this setting.
Improve offlineTests error reporting

 - put the ivy repo report in separate spot for dist and
   integration-tests instead of one overwriting the other
 - dump prolems, evictions, artifacts in addition to deps
   to the report
 - when offlineTests fails, helpfully print where the report
   lives and which tests failed
Use non-uuid names in target/ for offline project updates

This way people can manually mess with the test projects
and debug problems.
Collect all errors from offline tests and show them at end

This way you don't have to scroll back through loads of junk.
Log the offline test sbt command
Merge pull request #613 from typesafehub/wip/havocp-offline-reporting

Make offlineTests easier to debug
Bump template cache to c7d7612de6f48463b962d3727d226be3aacd218c

This breaks the build since offline deps aren't updated to match.
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.
Use 2.11-based sbt for sbt-remote-control and activator-template-cache and ourselves
Akka version 2.3.3 => 2.3.4
Use sbt-rc 7be0ef2928241f9d13137c7cb90f1c30238f1d25

This one uses sbt-echo 0.1.4 which is not broken.