- merged inline inserts branch

- merged inline inserts branch
- all executemany() style calls put all sequences and SQL defaults inline into a single SQL statement
and don't do any pre-execution
- regular Insert and Update objects can have inline=True, forcing all executions to be inlined.
- no last_inserted_ids(), lastrow_has_defaults() available with inline execution
- calculation of pre/post execute pushed into compiler; DefaultExecutionContext greatly simplified
- fixed postgres reflection of primary key columns with no sequence/default generator, sets autoincrement=False
- fixed postgres executemany() behavior regarding sequences present, not present, passivedefaults, etc.
- all tests pass for sqlite, mysql, postgres; oracle tests pass as well as they did previously including all
insert/update/default functionality