Minimum average time added, below which no new channels are created

Configurable minimum average waiting time in the queue, below which no
new channels are created, and above which no channels are destroyed.
Merge pull request #64 from grabmill/master

Minimum average time added, below which no new channels are created

Thanks for this, this should fix #64 for the time being. At some point I'd like to introduce some different logic for scaling, however I'm not quite sure what the best way to do that is, and there's currently bigger fish to fry in the project (like a client library abstraction layer).

Thanks for your contribution here, you rock!
Fixed tab/spacing
Fixed tab/spacing
Fixes #72

Fixed the tile header target string, also added event raising for device
subscription expired in windows phone
Fixes #65

Also bumped versioning
NuGet Release