Documentation changes to warn that sqlite3_set_auxdata() might call the
destructor even before it returns.  Also fix the regexp extension to deal
with that case.  Ticket [406d3b2ef91c].
Fix a 8-byte alignment problem in the query planner that might cause
problems on sparc when compiled with -m32.
Ensure that all auxiliary data registered by calls to sqlite3_set_auxdata() is destroyed when the VM is halted. Partial fix for [406d3b2ef9].
Fix a typo in the previous commit.
Ensure that all auxiliary data registered by calls to sqlite3_set_auxdata() is destroyed when the VM is halted.
Improved documentation for sqlite3_set_auxdata().
Ticket [406d3b2ef91c].
Remove unused "codec" code from the command-line shell.