Add Extended Modem Status frame type (0x98)

This commit adds support for the Extended Modem Status
frame type 0x98 as implemented in XBee S2C modules.
Reporting of Extended Modem Status is enabled with the
ATDC10 command.

Author: Scytmo

xbee/zigbee.py

@@ -162,6 +162,13 @@ class ZigBee(XBeeBase):
                 {'name':'status',             'len':1}
             ]
         },
+        b'\x98': {
+            'name': 'extended_status',
+            'structure': [
+                {'name': 'status',            'len': 1},
+                {'name': 'data',              'len': None}
+            ]
+        },
         b'\x8D': {
             'name': 'route_information',
             'structure': [