Do not save default values

session/bool.go

@@ -17,6 +17,9 @@ func (this *Session) GetBool(name string, def bool) bool {
 }
 
 func (this *Session) SetBool(name string, value bool) {
+	isset := this.IsSetBool(name)
 	this.v.Bool[name] = value
-	this.c = true
+	if !(isset == false && value == false) {
+		this.c = true
+	}
 }

session/int.go

@@ -17,6 +17,9 @@ func (this *Session) GetInt(name string, def int) int {
 }
 
 func (this *Session) SetInt(name string, value int) {
+	isset := this.IsSetInt(name)
 	this.v.Int[name] = value
-	this.c = true
+	if !(isset == false && value == 0) {
+		this.c = true
+	}
 }

session/string.go

@@ -17,6 +17,9 @@ func (this *Session) GetString(name string, def string) string {
 }
 
 func (this *Session) SetString(name string, value string) {
+	isset := this.IsSetString(name)
 	this.v.String[name] = value
-	this.c = true
+	if !(isset == false && value == "") {
+		this.c = true
+	}
 }