Remove prototypes

They're provided by output.h and are thus, redundant.
Remove unneeded include.
Move comment to reflect the coding style I use.
Use the code in output.c.
Update Makefile to make new libspcdnsmisc libraries.

The libspcdnsmisc library contains code from netsimple.c and output.c to
facilitate initial application development.
Update README with a blurb about where to find the output routines.
Update rockspec for new version.
Makefile: compile with -O2 by default