Update references of package names to com.github.dozermapper

[garethahealy]

As we are releasing under the com.github.dozermapper group id, the packages should also match.

[buzdin]

Sort of, but then expect a lot of complaints from the community. Is it really worth it?

[garethahealy]

I would expect 99.99% of people who use dozer are using either eclipse or intellij, which with a few shortcuts can update and replace any package changes, so i dont see it as a big problem. Its a one-off change for the end-user.