* The existing methods TranslateBy(), ScaleBy() and RotateBy()
transform the transformation. For a transform A, a point p,
and the temporary transform B (being applied by the methods),
this results in p' = B*(A*p) = (B*A)*p
This is not necessarily the desired result. Suppose A is a
translation and B a rotation, added by RotateBy(). Then B*A
means that the translation itself is rotated, so B moves the
coordinate origin itself, by rotating it around the original
origin of the coordinate system (top left view corner).
If we want to translate and then rotate around that *new* origin,
we need to multiply the transforms the other way around: A*B.
Three new methods PreTranslateBy(), PreScaleBy() and PreRotateBy()
implement this. They are later used as a base to add translatation/
scaling/rotation methods to BView which behave in the expected
ordering, similar to other graphic APIs.
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