Added reflection to sqlalchemy.dialects.sybase

Added reflection to sqlalchemy.dialects.sybase

Added missing types supported by Sybase to ischema_names mapping

Created a SybaseInspector similar to the PGInspector, with a cached table_id
  lookup, and added it to the SybaseDialect as the default inspector.

Added the following methods to SybaseDialect:
  get_table_id
  get_columns
  _get_column_info : support method for get_columns
  get_foreign_keys
  get_indexes
  get_pk_constraint
  get_schema_names
  get_view_definition
  get_view_names
Rewrote the following methods to conform to the style of the rest:
  get_table_names
  has_table

Reordered colspec builder to put default clause after "NULL/NOT NULL",
  instead of before.  This fixed a syntax error.