Beast fails to initialize model when the number of states is different. #15
Description
When using the ordinal model and ordinal data with a different number of states, beast fails to initialize the model giving -infinite likelihood.
This is an input user error and should be caught during the model verification stage (such as when the sum of frequencies is checked) and communicated with an appropriate error.
During creating a sample test case with short sequences, beast even managed to run (although gave a few "incorrect likelihood was calculated" errors), this should not have happened.
Suggested fix: Additional assert/check that the number of states in the model agrees with the data.
Sample example: XML with randomly generated sequences and, to my best knowledge, vanilla ordinal model specification.