Updates references from using underscore filenames to hyphen filenames for files...

Updates references from using underscore filenames to hyphen filenames for files under src/

Commit automatically generated using these commands on a clean tree:
$(for file in $(find src/ -iname '*_*.[ch]' -type f); do export file=$(basename "$file"); echo "$file"; ruby -pi -e 'us_fi=ENV["file"]; us_re=Regexp.new("(?<!\\w)"+Regexp.escape(us_fi)+"(?=\\W)"); hyphen_file=us_fi.gsub(/_/, "-"); $_.gsub!(us_re, hyphen_file)' $(find * -type f | egrep -v 'ChangeLog|\.png|\.icc') ; echo; done)
$(for file in $(find src/ -iname '*_*' -type d); do export file=$(basename "$file"); echo "$file"; ruby -pi -e 'us_fi=ENV["file"]; us_re=Regexp.new("(?<!\\w)"+Regexp.escape(us_fi)+"(?=\\W)"); hyphen_file=us_fi.gsub(/_/, "-"); $_.gsub!(us_re, hyphen_file)' $(find * -type f | egrep -v 'ChangeLog|\.png|\.icc') ; echo; done)

Followed by a manual touchup in src/typedefs.h