Fix the _SIP1D class by making it subclass PolynomialBase and bringing it closer in functionality to other PolynomialBase subclasses.  Really it would be best if this subclassed Polynomial2D, but that will require a little refactoring of how the polynomial models work.  For one, it would be nice to easily customize the parameter name format.
Add a SIP forward transforation test. Correct a bug in calculating the number of SIP coefficients.
Add a SIP forward transforation test. Correct a bug in calculating the number of SIP coefficients.
Allow polynomial coefficients to have somewhat arbitrary names (c prefix is still the default). Fix inverse sip to be a full polynomial, applied directly to the input.
add the 0th term only in the inverse class
add a test for inverse sip
add missing data file
Merge pull request #9 from nden/sip-examples

Sip examples