------------------------------
- support for NOTIFY callbacks via 'addNotifyObserver()'
- many robustness fixes making txpostgres more stable under heavy
loads (thanks to Andrey Smirnov and Tobias Oberstein for bug
reports and patches)
- comatibility with psycopg2 > 2.4.2 (thanks to Erik Allik and
Vasily Evseenko)
- txpostgres now falls back to psycopg2-ctypes if psycopg2 is not
found (thanks to Vasily Evseenko)
- fix problem with Twisted < 11.1.0 and the Gtk2 reactor (thanks to
Marek Kowalski)
- fixes for log spew when handling severed connections, txpostgres
now tries to report exactly one error in such events