mavutil.py: default to using 'all' dialect in place of ardupilotmega

Author: peterbarker

mavutil.py

@@ -19,10 +19,10 @@
 from pymavlink.generator.mavcrc import x25crc as x25crc
 
 # adding these extra imports allows pymavlink to be used directly with pyinstaller
-# without having complex spec files. To allow for installs that don't have ardupilotmega
+# without having complex spec files. To allow for installs that don't have the "all" dialect
 # at all we avoid throwing an exception if it isn't installed
 try:
-    from pymavlink.dialects.v10 import ardupilotmega
+    from pymavlink.dialects.v10 import all
 except Exception:
     pass
 
@@ -45,7 +45,7 @@
 
 # Use a globally-set MAVLink dialect if one has been specified as an environment variable.
 if not 'MAVLINK_DIALECT' in os.environ:
-    os.environ['MAVLINK_DIALECT'] = 'ardupilotmega'
+    os.environ['MAVLINK_DIALECT'] = 'all'
 
 def mavlink10():
     '''return True if using MAVLink 1.0 or later'''