Move conversion functions into namespace util.

Similar to the printable and parseable concept, we now have move the related
conversion functions into namespace util. Due to unresolved ADL issues,
however, these free functions do not yet live in namespace util, but we intend
to move them there in the future.
Rename sequence range base class.
Formatting nit.
Fix bug in EWAH bitstream iteration.
Uncouple segment extraction and bitstreams.
Add macro to log actor IDs.
Fix off-by-one during bitmap index 0-filling.
Perform maintenance of the query processor.