making sure that the coeff-vals ordering is correct.
making alias work with the new coeff ordering
making simplify work with the new coeff ordering.
making trigcoeffs work with the new coeff ordering.
making feval work with the new coeff ordering.
making appropriate changes in tests
making roots and diff work.
making cumsum work
all trigtech tests pass!
changing help text in coeffs2vals and vals2coeffs to match the coeff ordering.
Improving documentation.
Merge pull request #1196 from chebfun/fix-trigcoeffs

Fix trigcoeffs