Beginning to move to using Activator.

Doesn't fully compile yet, but at least we are now resolving all of the
dependencies. (Except akka-testkit, which is still a mystery, but I'm not
actually using it yet anyway.)
Figured out how to get akka-testkit to resolve.

Yay for the Sonatype browser!
Got the Controller layer mostly working in Activator.

Note that Eclipse is showing spurious failures on the views.
Lots of progress towards compiling

Not there yet, but down to only 11 errors.
Made RT invariant, since the compiler is demanding it

Pretty much from the beginning, RT has been contravariant, because my
initial experiments needed that. But the compiler complains about PType's
realType being set to a contravariant type parameter, and I don't think we
turn out to care much -- RT is more a convenience than a central element.
So let's try making it invariant.
Brought LoggingFilter up to Play 2.3 spec

Main change is that everything is Futures now.
Replaced a now-deprecated class.

Hopefully correctly.
Fixed another couple of more-minor compile problems.

Another contravariance problem, and changed out a deprecated method.
Removed usage of the now-deprecated twitterBootstrap integration.
Fixed a severe bug that was preventing Space creation.

Basically, we were trying to create a Thing in the Space before we
evolved the Space; this caused the process to crash.