- improved pool docs
- typos etc.
- ClauseElement.execute() and scalar() make no sense - these are depreacted.
The official home is Executable.
- alias() is not executable, allowing it is sloppy so this goes under
the deprecated umbrella
oriented situation, will at least return NULLTYPE
for its type instead of None, allowing it to
be used a little more freely for ad-hoc column
expressions than before. literal_column()
is still the better choice, however.