table/schema/owner component formatter for ANSIIdentifierPreparer

[jek]

From #482:

... passing the full table in to has_table() still does not eliminate the complexity that some dialects need to query the schema name and tablename as separate columns, so the format_table() method is not flexible enough. a new method "foramt_schema_and_tablename" or similar should be added to ANSIIdentifierPreparer which returns the two names separately, and is called by the generic create/drop methods in ansisql.py to get the quoted names, which then get passed to has_table ...

This new method could return formatted identifiers for the whole path to a table (#594) as a list, and the dialect can '.'.join() them or use them piecemeal as needed.

[jek]

c4130498c08552242797a698309af43ed5fff50c is a start on this

[Mike Bayer]

Removing milestone: 0.4.0 (automated comment)