Use instr for substring test in SQL query

There is no longer a need for the EscapeGlob function.

store/sql.go

@@ -1,11 +0,0 @@
-package store
-
-import "strings"
-
-var globEscaper = strings.NewReplacer("\\", "\\\\", "?", "\\?", "*", "\\*")
-
-// EscapeGlob escapes s to be suitable as an argument to SQLite's GLOB
-// operator.
-func EscapeGlob(s string) string {
-	return globEscaper.Replace(s)
-}

store/visited_dir.go

@@ -51,8 +51,7 @@ func convertVisitedDirs(rows *sql.Rows) ([]VisitedDir, error) {
 
 func (s *Store) FindVisitedDirs(p string) ([]VisitedDir, error) {
 	rows, err := s.db.Query(
-		"select path, score from visited_dir where path glob ? order by score desc",
-		"*"+EscapeGlob(p)+"*")
+		"select path, score from visited_dir where instr(path, ?) > 0 order by score desc", p)
 	if err != nil {
 		return nil, err
 	}