Fix trailing whitespace, typos, headers

Fix trailing whitespace, typos, and header uniformity.

src/Base/RotationPy.xml

@@ -54,7 +54,7 @@ z : float
 w : float\n
 Rotation(dir1, dir2, dir3, seq)
 Define from three vectors that define rotated axes directions plus an optional
-3-characher string of capital letters 'X', 'Y', 'Z' that sets the order of 
+3-characher string of capital letters 'X', 'Y', 'Z' that sets the order of
 importance of the axes (e.g., 'ZXY' means z direction is followed strictly,
 x is used but corrected if necessary, y is ignored).
 dir1 : Base.Vector