Add support for month/weekday callbacks in moment.fn.format
For reference, here is the file size increase.
I don't think that we can accept this pull request if it doesn't have any tests for the second code branch. There are currently no languages that have these callbacks, so we could either write tests that add a callback and run it, or we could wait until the Russian changes are made.
Adding in month and weekday callback functions and tests.
#313 #325 #312
This PR is useless with the new formatter, but I did add the functionality in with another commit.
I added unit tests as well with a dummy language, so at least we have coverage.
Another language had reason to use these callbacks, so I though it would be good to merge in so TR and RU can write code against it.