Base: add new API Rotation::get/setEulerAngles()

Exposed to Python as new constructor parameters and
Rotation.toEulerAngles()

This function uses the code from OCCT
gp_Quaternion::Get/SetEulerAngles() to support all 24 possible
generalized euler rotation sequences. Call Rotation.toEulerAngles()
without argument to obtain all possible sequence types.

src/Base/RotationPy.xml

@@ -24,6 +24,8 @@
 				-- a Vector (axis) and a float (angle)
 				-- two Vectors (rotation from/to vector)
 				-- three floats (Euler angles) as yaw-pitch-roll in XY'Z'' convention
+                -- one string and three floats (Euler angles) as euler rotation 
+                   of a given type. Call toEulerSequence() for supported sequence types.
 				-- four floats (Quaternion) where the quaternion is specified as:
 				   q=xi+yj+zk+w, i.e. the last parameter is the real part
 				-- three vectors that define rotated axes directions + an optional
@@ -84,12 +86,21 @@
         <Methode Name="toEuler" Const="true">
 			<Documentation>
 				<UserDocu>
-					toEuler(Vector) -> list
+					toEuler() -> list
 					Get the Euler angles of this rotation
 					as yaw-pitch-roll in XY'Z'' convention
 				</UserDocu>
 			</Documentation>
 		</Methode>
+        <Methode Name="toEulerAngles" Const="true">
+			<Documentation>
+				<UserDocu>
+					toEulerAngles(seq='') -> list
+                    Get the Euler angles in a given sequence for this rotation.
+                    Call this function without arguments to output all possible values of 'seq'.
+				</UserDocu>
+			</Documentation>
+		</Methode>
         <Methode Name="toMatrix" Const="true">
 			<Documentation>
 				<UserDocu>