Status of io.sql.get_schema as public function?
At this moment, `pd.io.sql.get_schema` is not documented (not in the API docs, and not in the io docs). But, it is a potential useful function, so I think it would be good to be more explicit about its status (by mentioning it in the docs).

However, there are some quirks about the function:
- The signature: `pd.io.sql.get_schema(frame, name, flavor='sqlite', keys=None, con=Non
  e, dtype=None)` -> flavor keyword in the third place, while we want to deprecate it (and this means you cannot do `get_schema(df, 'name', engine)`, but always have to do `get_schema(df, 'name', con=engine)`.  
  Ideally this should have the same arguments (order) as `to_sql` (`pd.io.sql.to_sql(frame, name, con, flavor='sqlite', schema=None, if_exists='fail', index=True, index_label=None, chunksize=None, dtype=None)`) (only chunksize is not relevant)
- It should have all options to modify the resulting sql table as `to_sql`
- Maybe also the option to return the sqlalchemy `Table` instead of the string itself?

That we maybe should first solve before making it more explicitely public?

Triggered by http://stackoverflow.com/questions/29749356/python-pandas-export-structure-only-no-rows-of-a-dataframe-to-sql/
