python: Servo: add Navio+ support

Add root check
Add Navio+ entry and add shield auto choice

Author: Igor Anokhin

Python/Servo.py

@@ -1,21 +1,29 @@
-import sys
 import time
+import os
 
-import navio.pwm
-import navio.util
+import navio.Common.util
 
-navio.util.check_apm()
+if navio.Common.util.get_navio_version() == "NAVIO2":
+	import navio.Navio2.RCOutput as RCOutput
+else:
+	import navio.Navio.RCOutput as RCOutput
 
+SERVO_MIN = 1.250  # ms
+SERVO_MAX = 1.750  # ms
 PWM_OUTPUT = 0
-SERVO_MIN = 1.250 #ms
-SERVO_MAX = 1.750 #ms
 
-with navio.pwm.PWM(PWM_OUTPUT) as pwm:
-    pwm.set_period(50)
-    pwm.enable()
+if (os.getuid() != 0):
+    print "Not root. Please, launch like this: sudo python Servo.py"
+    exit(-1)
 
-    while (True):
-        pwm.set_duty_cycle(SERVO_MIN)
-        time.sleep(1)
-        pwm.set_duty_cycle(SERVO_MAX)
-        time.sleep(1)
+navio.Common.util.check_apm()
+
+with RCOutput(PWM_OUTPUT) as pwm:
+	pwm.set_period(50)
+	pwm.enable()
+
+	while (True):
+		pwm.set_duty_cycle(SERVO_MIN)
+		time.sleep(1)
+		pwm.set_duty_cycle(SERVO_MAX)
+		time.sleep(1)