Makefile: Statically link jit.* modules from LuaJIT.

Thanks Mike Pall for telling me how to do this.
Imported Mike Pall's experimental tporf.lua and vmprof.c.

tprof.lua is a simple application profiler written in Lua.
Example:
  snabbswitch -l jit.tprof -e 'jit.tprof.on()' -l selftest -e 'jit.tprof.off()'

vmprof.c is a hardcore runtime system profiler written in C.
I haven't worked out how to use it yet :-)
'make book': Create a book version of Snabb Switch code.

Create snabbswitch.pdf (and .html and .epub) by very lightly
converting the sources to Markdown and then running them through
pandoc.

See doc/genbook.sh for the main glue.
intel.lua: Converted to ASCII.

Removed some Unicode characters that had come in via copy & paste from
the data sheet.
Superficial layout changes.

To make sources pretty-print in book format better.