- fix emitrules() like emitfiles() to deal with the prefix (otherwise it
would attempt to find the file in the normal base for the NORMAL_C rule).
- add emitincludes() which adds include directives for each prefix to the
$INCLUDES variable in the makefile.
- add %INCLUDES to each Makefile.arch to deal with the above.
this makes "prefix" actually work in a usable manner, and now i can move
on to fixing compiler warnings (errors) in the ESP code. :)
ecdad0ec33