SE/FS: Build the devices in SE mode.

scons: rename TraceFlags to DebugFlags

rename AlphaConsole to AlphaBackdoor

Devices: Separate out the MC146818 RTC so both Alpha and X86 can use it.

Traceflags: Add SCons function to created a traceflag instead of having one file with them all.

Move SimObject python files alongside the C++ and fix
the SConscript files so that only the objects that are
actually available in a given build are compiled in.
Remove a bunch of files that aren't used anymore.

Rework the way SCons recurses into subdirectories, making it
automatic. The point is that now a subdirectory can be added
to the build process just by creating a SConscript file in it.
The process has two passes. On the first pass, all subdirs
of the root of the tree are searched for SConsopts files.
These files contain any command line options that ought to be
added for a particular subdirectory. On the second pass,
all subdirs of the src directory are searched for SConscript
files. These files describe how to build any given subdirectory.
I have added a Source() function. Any file (relative to the
directory in which the SConscript resides) passed to that
function is added to the build. Clean up everything to take
advantage of Source().
function is added to the list of files to be built.

Get rid of pcifake.cc and tsunami_fake.cc to go with the merged default devices.

Moved the tsunami devices into the dev/alpha directory. Other devices "generic" devices are dependent on some of those files. That will either need to change, or most likely those devices will have to be considered architecture dependent.

Created seperate SConscript for the dev directory. Made subdirectories for Alpha and SPARC and put SConscripts in them.