Logging improvements (#195)

- Fix (and test) filtering of lines
- Filter out shadowsocks cannot resolve error
- Change tinyproxy color
- Deduct logging level according to message content

internal/constants/colors.go

@@ -2,22 +2,22 @@ package constants
 
 import "github.com/fatih/color"
 
-func ColorUnbound() color.Color {
-	return *color.New(color.FgCyan)
+func ColorUnbound() *color.Color {
+	return color.New(color.FgCyan)
 }
 
-func ColorTinyproxy() color.Color {
-	return *color.New(color.FgHiMagenta)
+func ColorTinyproxy() *color.Color {
+	return color.New(color.FgHiGreen)
 }
 
-func ColorShadowsocks() color.Color {
-	return *color.New(color.FgHiYellow)
+func ColorShadowsocks() *color.Color {
+	return color.New(color.FgHiYellow)
 }
 
-func ColorShadowsocksError() color.Color {
-	return *color.New(color.FgHiRed)
+func ColorShadowsocksError() *color.Color {
+	return color.New(color.FgHiRed)
 }
 
-func ColorOpenvpn() color.Color {
-	return *color.New(color.FgHiMagenta)
+func ColorOpenvpn() *color.Color {
+	return color.New(color.FgHiMagenta)
 }