Rename the equal_to() function to compare_to() to avoid name conflict in gcc-4.4.7 compiler.
Any test that was using equal_to() was failing.  Re-ran the tests and they all pass now.
Resolve issue #7902: Bugs: Division by scalar should use enable_if<>

- This is almost identical to the fix used on #6511: Bugs: Division
  by scalar should use enable_if<> (closed: fixed)
- Scalar multiply was allowed, but divide was not.
- Updated test13 to include test of this capability
- Scaling a matrix now includes two more lines for division
  1. * m1 = [3,3]((1,2,3),(4,5,6),(7,8,9))
  N * m1 = [3,3]((3,6,9),(12,15,18),(21,24,27))
  m1 * 1. = [3,3]((1,2,3),(4,5,6),(7,8,9))
  m1 * N = [3,3]((3,6,9),(12,15,18),(21,24,27))
  m1 / 2. = [3,3]((0.5,1,1.5),(2,2.5,3),(3.5,4,4.5))
  m1 / N = [3,3]((0.333333,0.666667,1),(1.33333,1.66667,2),(2.33333,2.66667,3))