Fix comment wrt KDBUS_MSG_FLAGS_WAIT_FOR_REPLY

This flag does not exist, fix it before more people get confused.
connection: fix expect_reply logic

Only interpret msg->cookie_reply if KDBUS_MSG_FLAGS_EXPECT_REPLY isn't
set. Re-order the code and add some comments.
kdbus_conn_move_messages: Use kdbus_conn_queue_remove()

Cleanup the original connection's queue properly by calling
kdbus_conn_queue_remove().
kdbus_pool_copy(): increase off_src in loop

off_src is used by kdbus_pool_copy_file() to determine the offset in the
source file to copy from. We need to increase it by the number of copied
bytes after each call.

This fixes pool-to-pool copies with slices larger that PAGE_SIZE.
connection: comment cleanup
pool: kdbus_pool_copy(): increment context-specific variables conditionally
kdbus_pool_copy: use offset + "pos" instead in both cases
domain: create sub-domain from parent domain
check for disconnected parent objects before linking into them
ensure we never have any children objects linked when we free a parent
move function around
connection: update kernel doc
names: rename "entries_lock" to "lock"
connection: do not add messages to dead connection
connection: release names before dropping messages

Messages might need to move back to the activator, if we drop them first,
there is nothing to move left.
names: remove unused hash variable
names: do not allow to add names to dead connections
names: kdbus_name_replace_owner - guard against connection disconnect
endpoint: free the policy_db on error path

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
test-kdbus: rename check bus and domain functions

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>