Rename field names to prevent misunderstanding

The roll-pitch-yaw convention differs among industries, thus, is better
to explicitly state the axis which rotation is considered. The field
names also explicitly states that the values are "angular velocity" and
"linear acceleration," as opposed to "orientation" and "motion," which
are ambiguous (and technically incorrect).

ds4drv/device.py

@@ -41,12 +41,12 @@ class DS4Report(object):
                  "button_options",
                  "button_trackpad",
                  "button_ps",
-                 "orientation_roll",
-                 "orientation_pitch",
-                 "orientation_yaw",
-                 "motion_x",
-                 "motion_y",
-                 "motion_z",
+                 "ang_vel_x",
+                 "ang_vel_y",
+                 "ang_vel_z",
+                 "lin_acc_x",
+                 "lin_acc_y",
+                 "lin_acc_z",
                  "trackpad_touch0_id",
                  "trackpad_touch0_active",
                  "trackpad_touch0_x",
@@ -181,12 +181,12 @@ def parse_report(self, buf):
             # Trackpad and PS buttons
             (buf[7] & 2) != 0, (buf[7] & 1) != 0,
 
-            # Orientation
+            # Angular velocity
             S16LE.unpack_from(buf, 13)[0],
             S16LE.unpack_from(buf, 15)[0],
             S16LE.unpack_from(buf, 17)[0],
 
-            # Acceleration
+            # Linear acceleration
             S16LE.unpack_from(buf, 19)[0],
             S16LE.unpack_from(buf, 21)[0],
             S16LE.unpack_from(buf, 23)[0],