Include limits set in the resource summary

The limits set are printed in the summary with the prefix "limits_".
This can be used to record what resources where requested, from which we
can compute an estimate of resources wasted.
Rewrite monitor command until the last moment

Now we keep separate the monitoring command from the original 'vanilla'
command, and rewrite the monitoring command just before the node is
dispatched to the batch interface.  This to allows the modification of
the monitoring command when resources are exceeded.
Read multiple summaries from stream

This allows to read multiple summaries from a single file, as they come
from the resource archive.
Monitor for all resources (not only disk and memory).
Increase resources requested when limits exceeded.

When a task fails because of resources limits, it is rescheduled with an
increase on the resources requested.  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 use some cleaning too.
Monitor with two sets of limits in Makeflow per rule.

Each category defines two sets of limits, std_resources and
max_resources. std_resources represents the initial resources requested,
while max_resources represents the maximum value the original
std_resources may be increased when retrying a rule.
Basic statistics from histograms to table.
Simple script to query the archive
ooexample