Stop smobifying Transform (issue 567580043 by address@hidden)

[dak]

Rationale?  This negates work done as part of issue 5347 with the
long-term goal of making transforms a better integrated and accessible
part of stencils.  This will be increasingly important when we move to
Cairo since Cairo cannot represent rotations by multiples of 90 degrees
cleanly other than by using an explicit transform matrix since (in
defiance of all other graphical systems like Postscript, PDF, METAPOST)
it refuses to represent angles in any other form than as radians (an
actual patch implementing angles as degrees was proferred and rejected
on what can hardly be called anything but philosophical grounds), and PI
does not have an exact representation in those.

https://codereview.appspot.com/567580043/