Add cpustates output processor. This is more-or-less a port of the
cpustates processor from WA, however there are some differences:
- Idle states are now tracked individually per-CPU. This will fix
processing traces from targets that have different number of idle
states on different clusters.
- Simplify the parameter list for report_power_stats:
- Replace paths to individual report files with a path to a single
directory. A subdirectory will be created under it which will
contain all the reports.
- Replace the individual bits bits of information about CPUs (core
names, idle states, etc) with a list of CpuInfo objects.
- Clean up and simplify the code a bit:
- Make all reports mandatory -- the marginal cost of generating
an additional report is minimal compared to tracking power states
in the first place.
- Standardize the interface for Reporters and Reports.
- Rename some of the reports to something a bit more meaningful.
- The stand-alone command line interface is not ported for now, as it
is now possible to run this offline on existing results using
"wa process".
