PC-BSD/trueos 61c0685sys/dev/syscons scterm-sc.c sctermvar.h

Restore syscons' terminal emulators.  The trivial fixes to make them compile
will be committed later.

The "sc" emulator has the advantages of full support for cons25 and running
about 8 times faster than teken (for writing to the frame buffer).

The "dumb" emulator has the advantage of being simple.

Runtime choice of the emulator is good, but compile time choice is bad.
DeltaFile
+811-0sys/dev/syscons/scterm-sc.c
+432-0sys/dev/syscons/sctermvar.h
+155-0sys/dev/syscons/scterm-dumb.c
+1,398-03 files

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