bit

A few minor changes and a few code cleanups, but mostly a stable pre-0.5 release.

This minor release makes all bit::Data comparison
operators const methods, allowing for comparison
of const data items.

bit::Data was moved to a deep allocation mechanism to allow for a more natural copy syntax.

This release now supports both boost and std::tr1
smart pointers. The Buffer and RecordBuffer
classes have been restructured, and xml support
has been added to the Field/Record hierarchy. This
release also contains a new record layout DTD that
supports type hints. Roughly 150 unit tests have
been added to the testing suite, along with other
small changes and bugfixes.

A potential type-punning issue when changing endianness for doubles and floats has been fixed. The documentation distribution has been cleaned up a bit.