search for TV spec in filename now ignores the path component

for example, in ROM Hunter's archive there are directories called "PAL
VERSIONS OF NTSC ORIGINALS" and "NTSC VERSIONS OF PAL ORIGINALS". these
cause false positives in the TV spec search

Author: JetSetIlly

hardware/television/specification/specifications.go

@@ -19,6 +19,7 @@ package specification
 
 import (
 	"image/color"
+	"path/filepath"
 	"strings"
 
 	"github.com/jetsetilly/gopher2600/hardware/television/signal"
@@ -39,6 +40,14 @@ func SearchSpec(s string) string {
 	// actually "PAL60".
 	var list = []string{"pal-60", "pal60", "pal-m", "palm", "ntsc", "pal", "secam"}
 
+	// we don't want to include the path in the search because this may cause
+	// false positives. for example, in ROM Hunter's archive there are
+	// directories called "PAL VERSIONS OF NTSC ORIGINALS" and "NTSC VERSIONS OF
+	// PAL ORIGINALS"
+	//
+	// http://www.atarimania.com/rom_collection_archive_atari_2600_roms.html
+	s = filepath.Base(s)
+
 	// look for any settings embedded in the filename
 	s = strings.ToLower(s)
 	for _, spec := range list {