I/O changes and SkipFuncEvents to increase FreeBSD compatibility.

I/O changes and SkipFuncEvents to increase FreeBSD compatibility.

SConscript:
    Added kern/freebsd/freebsd_events.cc.
arch/alpha/isa_traits.hh:
    Added Argument to support replacement of calibrate_clocks function in FreeBSD.
dev/ns_gige.hh:
    Fixed NIC model number typo.
dev/tsunami_io.cc:
    Added support for RTC writes and PIC 2 mask reads.  Made RTC static member.
dev/tsunami_io.hh:
    Made RTC static member.
kern/freebsd/freebsd_system.cc:
    Added events to skip functions in FreeBSD.
kern/freebsd/freebsd_system.hh:
    Added events to skip certain functions.

--HG--
extra : convert_revision : 8aaca51d3f9b1bb601722a5bae240aae77b445db