made unit types more consistant and more useful

Author: Brendan Whitfield

obd/utils.py

@@ -39,7 +39,7 @@ class Unit:
 	NONE    = None
 	RATIO   = "Ratio"
 	COUNT   = "Count"
-	PERCENT = "Percent"
+	PERCENT = "%"
 	RPM     = "RPM"
 	VOLT    = "Volt"
 	F       = "F"
@@ -48,9 +48,9 @@ class Unit:
 	MIN     = "Minute"
 	PA      = "Pa"
 	KPA     = "kPa"
-	PSI     = "PSI"
-	KPH     = "Kilometers per Hour"
-	MPH     = "Miles per Hour"
+	PSI     = "psi"
+	KPH     = "kph"
+	MPH     = "mph"
 	DEGREES = "Degrees"
 	GPS     = "Grams per Second"
 	MA      = "mA"