Fix memory leaks revealed by valgrind and ensuing code inspection.
In the existing test suite valgrind revealed two memory leaks (DB_get
and DBC_set_range). Code inspection revealed that there were many other
potential similar leaks (many on odd code error paths such as passing
something other than a DBTxn object for a txn= parameter or in the face
of an out of memory error). The most common case that would cause a
leak was when using recno or queue format databases with integer keys,
sometimes only with an exception exit.
features in BerkeleyDB not exposed. notably: the DB_MPOOLFILE interface
has not yet been wrapped in an object.
Adds support for building and installing bsddb3 in python2.3 that has
an older version of this module installed as bsddb without conflicts.
The pybsddb.sf.net build/packaged version of the module uses a
dynamicly loadable module called _pybsddb rather than _bsddb.
Gregory P. Smith