Move summary to common header.
Change struct tree_info to struct resources_info
Parsing single summaries from stream.
Printing/parsing of multiple summaries per file.
Summary resource file to json format output.
Prepare to pull out polling library.
Move mem monitoring to poll library.
Move io monitoring to poll library.
Move cpu-time monitoring to poll library.
Move wd footprint monitoring to poll library.
Polling once of proc/wd/fs to poll library.
Move polling all procs to poll library.
Eliminates limits exceeded global variable.
Print summary with a single function call.
Adds total count of process to summary/series.

num_processes counts the number of different processes created,
concurrent or not.

max_concurrent_processes was renamed to max_processes.
Reports only the original limit exceed.

When a limit is exceeded, the line written to the summary is, for
example:

limits_exceeded: wall_time: 2, num_processes: 10

Before it was:
limits_exceeded: wall_time: 2.02 > 2, num_processes: 11 > 10
Renames workdir_number_files_dirs to workdir_num_files.
Enable disk footprint for cctools hook by default.