Allow activator version to be pulled from ~/.activator/verison.properties.

This enables auto-upgrading if we want to finish wiring things through.
The basic gist is:

1. Detect if we're on the latest version of activator
2. If not, bump the version in version.properties
3. "Reboot" the application into the version found in version.properties.

This at least gets the initial startup correct, but not the live
rebooting.
Ensure offline repository is added to sbt-rc.

This should fix offline mode.  However, I couldn't find where/how
this was working without this fix.  This was created specifically
for offline  mode to work.   Not sure how we limped along
without it.
Add launcher repository config file location to boot properties.

Allows users to configure whatever remote repositories they want
via a global config file shared between sbt and activator.

Fixes #115
Bump to sbt-remote-control 7479a76acfa0019d33f30e3c657a7b3cdc9d0ba5

This one supports play 2.1.4, 2.1.5 and drops support for 2.1.3 and earlier.
Merge pull request #121 from typesafehub/wip/1.0.x-sync

Sync stuff in 1.0.x only to master