Added statistics collection infrastructure in Bochs and
implemented important CPU statistics which were used for Bochs CPU model performance analysis.
old statistics code from paging.cc and cpu.cc is replaced with new infrastructure.

In order to enale statitics collection in Bochs CPU:

- Enable statistics @ compilation time in cpu/cpustats.h
- Dump statistics periodically by adding -dumpstats N into Bochs command line


git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@12501 6c8e4198-a580-4521-a02f-c9ae86df1db9