pybootchartgui: support reading reduced /proc logs
Pre-processing /proc data during the build considerably reduces the
amount of data written to disk: 176KB instead of 4.7MB for a 20
minuted build. Parsing also becomes faster.
buildstats.bbclass only writes the reduced logs now, but support for
the full /proc files is kept around as reference.
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
