Fix broken Legendre polynomial test case

Address #83

The previous commit fixed the broken scaling for the Legendre
Polynomial bassis. However, the test case, which worked with the
broken scaling was not updated to work with the new (correct) scaling.
Furthermore the tests have been changed to explicitly calculate the
test comparison values by constructing the Legendre Polynomials in the
test.
Merge pull request #1 from wd15/issue83-LegendreScaling

Fix broken Legendre polynomial test case