document arguments for table, column, sequence, etc.

[Mike Bayer]

the "definining meta data" chapter needs docs for all the acceptable arguments.

[Mike Bayer]

I think this is mostly complete as of my last update to the table metadata section but feel free to proof it + close this item !

[Mike Bayer]

the arguments for "Table" are documented in the pydoc...since they are usually not needed beyond "autoload=True". however, should add a section "overriding reflected columns", and also document the upcoming create_all/drop_all/exists stuff which should be completed too.

[Mike Bayer]

this item is out of date. table args are documented pretty well at this point.