Updating makefiles
Merge branch 'master' of github.com:tjhladish/EpiFire

Conflicts:
	examples/Makefile
changed examples Makefile
Merge branch 'master' of github.com:tjhladish/EpiFire

Conflicts:
	examples/Makefile
Cleaned up example 6
write_edgelist() is a bit more sophisticated

Users can now specify whether node names or IDs should be output, and
what kind of separator should be used.