Added blank line to end of sigmet_raw.c, required for standard C.
sigmet_png_kml now inserts contents of SIGMET_KML_ICON_URL into content of kml icon element.
Quoted path names in sig_raw to handle white space.
Added -p option in Makefile to ensure executables are installed as such.
Executable scripts that take a Sigmet volume argument can take either the path to a Sigmet raw product volume, or the path to a fifo that a sigmet_raw daemon is monitoring.