Improve msr.py command line interface

Use a real argument parser with help and error handling.
Automatically try to load msr driver
Add interface to changebit (--setbit / --clearbit)
Give better error messages.
Support EVENTMAP variable in jevents

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Update jevents

- Add listevents, showevent programs
- Add format_raw_event interface