Merge branch 'settings-config'

With these changes, settings.json should only contain options that
have been modified from their default values. Micro will actively
options that are set to default values from the settings.json file.
To see a full list of settings and their defaults, see the "options"
documentation, as well as `micro -options`.

internal/action/command.go

@@ -480,6 +480,7 @@ func SetGlobalOptionNative(option string, nativeValue interface{}) error {
 
 	if !local {
 		config.GlobalSettings[option] = nativeValue
+		config.ModifiedSettings[option] = true
 
 		if option == "colorscheme" {
 			// LoadSyntaxFiles()

internal/config/settings.go

@@ -28,9 +28,14 @@ var (
 
 	// This is the raw parsed json
 	parsedSettings map[string]interface{}
+
+	// ModifiedSettings is a map of settings which should be written to disk
+	// because they have been modified by the user in this session
+	ModifiedSettings map[string]bool
 )
 
 func init() {
+	ModifiedSettings = make(map[string]bool)
 	parsedSettings = make(map[string]interface{})
 }
 
@@ -148,9 +153,26 @@ func InitLocalSettings(settings map[string]interface{}, path string) error {
 func WriteSettings(filename string) error {
 	var err error
 	if _, e := os.Stat(ConfigDir); e == nil {
+		defaults := DefaultGlobalSettings()
+
+		// remove any options froms parsedSettings that have since been marked as default
+		for k, v := range parsedSettings {
+			if !strings.HasPrefix(reflect.TypeOf(v).String(), "map") {
+				cur, okcur := GlobalSettings[k]
+				if def, ok := defaults[k]; ok && okcur && reflect.DeepEqual(cur, def) {
+					delete(parsedSettings, k)
+				}
+			}
+		}
+
+		// add any options to parsedSettings that have since been marked as non-default
 		for k, v := range GlobalSettings {
+			if def, ok := defaults[k]; !ok || !reflect.DeepEqual(v, def) {
+				if _, wr := ModifiedSettings[k]; wr {
 					parsedSettings[k] = v
 				}
+			}
+		}
 
 		txt, _ := json.MarshalIndent(parsedSettings, "", "    ")
 		err = ioutil.WriteFile(filename, append(txt, '\n'), 0644)
@@ -158,10 +180,23 @@ func WriteSettings(filename string) error {
 	return err
 }
 
+// OverwriteSettings writes the current settings to settings.json and
+// resets any user configuration of local settings present in settings.json
 func OverwriteSettings(filename string) error {
+	settings := make(map[string]interface{})
+
 	var err error
 	if _, e := os.Stat(ConfigDir); e == nil {
-		txt, _ := json.MarshalIndent(GlobalSettings, "", "    ")
+		defaults := DefaultGlobalSettings()
+		for k, v := range GlobalSettings {
+			if def, ok := defaults[k]; !ok || !reflect.DeepEqual(v, def) {
+				if _, wr := ModifiedSettings[k]; wr {
+					settings[k] = v
+				}
+			}
+		}
+
+		txt, _ := json.MarshalIndent(settings, "", "    ")
 		err = ioutil.WriteFile(filename, append(txt, '\n'), 0644)
 	}
 	return err