Revert "Lazy load Moose::Error::Default"

Revert "Lazy load Moose::Error::Default"

This reverts commit d4b0f089e5fc9ddbd38a0bd369bb170c5c62eaef.

This sort of lazy loading hurts anyone using Moose in a long-running
environment like FastCGI or mod_perl, since it means that the module
ends up being loaded once per process, as opposed to being loaded once
and shared across multiple procs.