Increase resources requested when limits exceeded.

When a task fails because of resources limits, a new category of
resources is created, based on the original one, and increasing the
limits of the exceeded resource. This continues until dag_max_try is
reached. The original resource summary is moved to
rule-job-id.summary.failure.%d (thus if the task exceeds resources 10
times, but works at the 11th try, we have 11 such summaries).

Right now the increase is hardwired to double the original request.
Future improvements are to have some flexibility on how requested
resources are increased, and also have an upper limit on the resources
requested. The code could some cleaning too.