Move special datatypes into drizzled:: namespace

There are several general data types in publicly in use in Drizzle. We eventually want them to go away, but until then, we need to not pollute the namespaces of folks using our headers with types like "bitmap". All of the following should be moved into the drizzled:: namespace, including all of the methods/functions that go along with them. While that's going on, renaming them to match drizzle naming policy wouldn't be terrible

HASH, Tree, List<>, Typelib, qsort_cmp, String, Dynamic_array, bitmap