The overly greedy blue-comment star matcher would make all C and C++
code in doxygen look good, but it messes with non-doxygen block comments.
By changing to this `containedin` blocking, we pickup the trailing
`)` and `}` characters that seem to be skipped if just doing the
ticked-region contained requirement.
Now the `'*'` characters in fixed-width blocks show up correctly,
with respect to how I write code. (I think doxygen also swallows
them anyhow, so the highlighting is more consistent with doxygen's
parser.)
Also on loading a file, everything looks better now.
I made `cpp.cplusplus` a hybrid filetype which tricks the vim
highlighting into believing that we're really in raw C++ for the
purposes of the core vim highlighting rules. My `cplusplus` type
adds more bits to the core stuff, but mostly exists to let
doxygen slip in the way that I want it to.
