Make MXRP a metarole (aka trait) rather than a subclass of Moose::Meta::Role

This makes it play nice(r) with other MooseX modules.
Fix docs to match reality - see RT #93755
Replace parameters with arguments for clarity
Merge pull request #1 from moose/autarch/make-it-a-trait

Makes MXRP a metarole rather than a subclass of Moose::Meta::Role
Add a .travis.yml
Add some test descriptions
Override with() exported from MXRP so it works inside a role {} block

This caused breakage if a role {} block called "with Foo" and loaded another
parameterized role. The role being loaded would end up using the metaclass set
in $CURRENT_METACLASS because that was in effect as the role was being loaded.

This broke with the recent changes that made MXRP a trait rather than
Moose::Meta::Role subclass. What happened is that the Moose::Exporter code
would try to get the current metaclass to apply the trait to and it would get
applied to the role currently being generated (the thing that called "with")
rather than the thing that used MXRP.

We can fix this by unsetting $CURRENT_METACLASS before calling with().

I'd note that this is all a bit insane. I'm pretty sure that we can fix this
by simply having Moose::Exporter get the $meta object from the call(s) to
->init_meta, since that method should always return the right $meta object!
Remove test for passing -metaclass to "use MXRP"

This is an artifact of a much earlier era in Moose extensions. No one should
be using this any more (if they ever did).
Changes for next release
basic dzilification
clean up entries in Changes file
add contributors to metadata
squash reformat changelog
make eol tests pass
add a t/zzz-check-breaks.t test
ensure namespaces are clean
weave pod
make pod coverage test pass
make pod spelling tests pass