Update parameter documentation & fix tests

Author: redgoldlace

asyncpg/connection.py

@@ -847,7 +847,7 @@ async def copy_to_table(self, table_name, *, source,
  An optional schema name to qualify the table.
 
  :param str where:
- An optional condition used to filter rows when copying.
+ An optional SQL expression used to filter rows when copying.
 
  .. note::
 
@@ -929,7 +929,7 @@ async def copy_records_to_table(self, table_name, *, records,
  An optional schema name to qualify the table.
 
  :param str where:
- An optional condition used to filter rows when copying.
+ An optional SQL expression used to filter rows when copying.
 
  .. note::
 
@@ -2390,7 +2390,8 @@ def _detect_server_capabilities(server_version, connection_settings):
  notifications=notifications,
  plpgsql=plpgsql,
  sql_reset=sql_reset,
- sql_close_all=sql_close_all
+ sql_close_all=sql_close_all,
+ sql_copy_from_where=sql_copy_from_where
  )