Issue 1307 by Derek Shockey, fix the same bug for RCPT.

Issue #1307, patch by Derek Shockey.
When "MAIL" is received without args, an exception happens instead of
sending a 501 syntax error response.

 - Fix bsddb.dbtables: Don't randomly corrupt newly inserted rows by
   picking a rowid string with null bytes in it.  Such rows could not
   later be deleted, modified or individually selected.  Existing
   bsdTableDb databases created with such rows are out of luck.
 - Use mkdtemp for the test_dbtables test database environment and
   clean it up afterwards using shutil.rmtree.

Fixes http://bugs.python.org/issue1233 - bsddb.dbshelve.DBShelf.append
was useless due to inverted logic.  Also adds a test case for RECNO dbs
to test_dbshelve.

See also https://bugs.launchpad.net/bugs/72505.

Fix Coverity 185-186:  If the passed in FILE is NULL, uninitialized memory
would be accessed.

on DBCursor.get (and a friends) when passing in a string key.

This code was broken if save() returned a negative number since i contained
a boolean value and then we compared i < 0 which should never be true.

Fix Coverity #158: Check the correct variable.

http://bugs.python.org/issue1053

 (backport from rev. 58204)

Fixes issue #1777530; backported from trunk.

to be orderable to properly represent them.
 (backport from rev. 58122)

 (backport from rev. 58119)

(backport from rev. 58117).