pm-graph v5.6

sleepgraph:
 - force usage of python3 instead of using system default
 - fix bugzilla 204773 (https://bugzilla.kernel.org/show_bug.cgi?id=204773)
 - fix issue of platform info not being reset in -multi (logs fill up)
 - change -ftop call to "pm_suspend", this is one level below state_store
 - add -wificheck command to read out the current wifi device details
 - change -wifi behavior to poll /proc/net/wireless for wifi connect
 - add wifi reconnect time to timeline, include time in summary column
 - add "fail on wifi_resume" to timeline and summary when wifi fails
 - add a set of commands to collect data before/after suspend in the log
 - add "-cmdinfo" command which prints out all the data collected
 - check for cmd info tools at start, print found/missing in green/red
 - fix kernel suspend time calculation: tool used to look for start of
    pm_suspend_console, but the order has changed. latest kernel starts
    with ksys_sync, use this instead
 - include time spent in mem/disk in the header (same as freeze/standby)
 - ignore turbostat 32-bit capability warnings
 - print to result.txt when -skiphtml is used, just say result: pass
 - don't exit on SIGTSTP, it's a ctrl-Z and the tool may come back
 - -multi argument supports duration as well as count: hours, minutes, seconds
 - update the -multi status output to be more informative
 - -maxfail sets maximum consecutive fails before a -multi run is aborted
 - in -summary, ignore dmesg/ftrace/html files that are 0 size

bootgraph:
 - force usage of python3 instead of using system default

README:
 - add endurance testing instructions

Makefile:
 - remove pycache on uninstall

Signed-off-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>