revise API: unexport ScanEnum to reconsider API
diff --git a/gcfg.go b/gcfg.go
index d0385d7..7d05ee4 100644
--- a/gcfg.go
+++ b/gcfg.go
@@ -38,7 +38,7 @@
 //    - support multiple inputs (readers, strings, files)
 //    - support declaring encoding (?)
 //    - support pointer fields
-//  - ScanEnum
+//  - scanEnum
 //    - should use longest match (?)
 //    - support matching on unique prefix (?)
 //  - writing gcfg files
@@ -84,7 +84,7 @@
 	"false": false, "no": false, "off": false, "0": false}
 
 func (b *gbool) Scan(state fmt.ScanState, verb rune) error {
-	v, err := ScanEnum(state, gboolValues, true)
+	v, err := scanEnum(state, gboolValues, true)
 	if err != nil {
 		return err
 	}
diff --git a/scanenum.go b/scanenum.go
index 5d35a2b..fa0a0d0 100644
--- a/scanenum.go
+++ b/scanenum.go
@@ -33,7 +33,7 @@
 // On I/O error, ScanEnum returns the I/O error, together with a nil value for
 // interface{}.
 //
-func ScanEnum(state fmt.ScanState, values map[string]interface{}, fold bool) (
+func scanEnum(state fmt.ScanState, values map[string]interface{}, fold bool) (
 	interface{}, error) {
 	//
 	rd := make([]rune, 0, scanEnumBufferHint)