Log Message:
Update to 2.6:

What's new in psycopg 2.6
-------------------------

New features:

- Added support for large objects larger than 2GB. Many thanks to Blake Rouse
  and the MAAS Team for the feature development.
- Python `time` objects with a tzinfo specified and PostgreSQL :sql:`timetz`
  data are converted into each other (:ticket:`#272`).

Bug fixes:

- Json apapter's `!str()` returns the adapted content instead of the `!repr()`
  (:ticket:`#191`).