Fix compile errors with some versions of GCC.

Some older & newer GCC have problems with the new BV code, but it's easily worked around.  Some were ambiguous uses of typedefs defined both in namespace "bv" as well as "bv::utils".  Another issue was in calling the copy-constructor of a CDList<>, which you aren't supposed to be able to do (it's protected), but for some reason compilers were permitting (I think the spec of our copy constructor is in error).