Ensure that re-invocations are time/count limited
Currently, although CloudFormation will eventually timeout on waiting for a resource provisioning action, there is no constraint on the duration or number of re-invocations that can be scheduled, leading to essentially unbounded Lambda compute.
Wrapper should auto-inject a net runtime into the callback context and use this to compute a restriction and eventual timeout at https://github.com/aws-cloudformation/aws-cloudformation-rpdk-java-plugin/blob/master/src/main/java/com/aws/cfn/LambdaWrapper.java#L262
This timeout should probably be slightly less than the CloudFormation timeout to ensure that stack events reflect actual progress and termination of handler occurs before CloudFormation abandons the request.
Related to #15 which lists additional requirements.
Partially implemented with #112