Proof-of-concept implementation of supporting bindparam for offset and limit on a query.
Expand test to also test whether offset accepts a bindparam.
Extract limit/offset to variables
Use _offset_clause and _limit_clause, which are always Visitable and usually a BindParameter, instead of _offset and _limit in GenerativeSelect.
Remove unused import
Pull out offset/limit to a local variable to reduce the impact of the inefficient select._offset and select._limit operations.
Remove unused import
Remove unused import
Remove unused import
Remove unused import
- experiment with multi-zoned navigation
Remove unused import
Another Variant for detecting if a connection is closed

If there is a closed attribute on the connection and
it is true, return true. Implements a todo in the code
and helps in one specific disconnect case where it previously
did not match because the error message was "unknown error".
Merge branch 'issue_3034' of https://bitbucket.org/dobesv/sqlalchemy/branch/issue_3034 into ticket_3034
- more tests, including backend tests
- implement for SQL server, use window functions when simple limit/offset not available
- some inlining, speed up identity map
remove events nobody uses...?
Revert "remove events nobody uses...?"

This reverts commit 72a09d9e5c54e3ee8b3561da144d8379ce1df747.
inlining
- mark translate_row, create_instance, populate_instance, append_result as legacy