Improve battery efficiency

Don't fire timers every 2sec, increase the timeout to 30sec and ensure
that shutdown doesn't have to wait the entire time
Merge pull request #176 from akavache/less-timers

Improve battery efficiency
Version bump to 4.0.2
Make tasks long-running so they don't block queues /cc @niik
Block for'evah
Package Patch
Add a test to verify keys throw if not found
These aren't necessary in this case because we're using the Blocking wrapper
Prove that Sqlite3 provider doesn't retrieve CreatedAt
Include CreatedAt in Select operations

Without this GetCreatedAt breaks for Sqlite3 backed caches.
Merge pull request #177 from akavache/niik/fix-sqlite3-created-at

Sqlite3 provider doesn't include CreatedAt in selects
Allow LockAsync to be canceled
Omg what is wrong with me, a boolean? CancellationToken!
Ensure Shutdown can't try to wait on itself
Ignore OperationCanceledException, it's what we wanted
Merge pull request #178 from akavache/nevar-deadlock

Make 100% sure we don't deadlock on exit
Version bump to 4.0.3
Attempt to fix CI build
Hotfix 4.0.3
I am an idiot.