Fix command argument appending function

Previously we always returned the first element. Now we return the
last one (the one we just allocated), which was intented in the first
place.
Merge pull request #297 from neithernut/fix-command-argument_appending

Fix command argument appending function
Add more extensive documentation about ws_connbuf
Add extensive documentation to ws_connector
Fix: ws_transaction_new() comparsion
Fix: deserializer_state(_new())

This patch fixes the deserializer_state type as well as the
deserializer_state_new() function. We don't need to cache the allocation
type here. It also adds an initialization for the bracket counting and
the ID (zero is an invalid ID now).
Fix: ws_transaction_push_statement()

This patch fixes the ws_transaction_push_statement() function by
doing a (almost) complete rewrite.

The code was tested in another branch.
Merge pull request #299 from matthiasbeyer/fix-for_json_deserializer

Fixes/Preparation for json deserializer
Merge pull request #294 from neithernut/add-connection-extensive_docu

Add more extensive documentation about ws_connbuf
Remove init callback from object.{c, h}
Remove init callback from object subtypes

Remove init callback from array.c, set.c, string.c and wayland_obj.c
Remove init callback in message subtypes

Remove init callback in error_reply.c, message.c, reply.c, transaction.c
and value_reply.c
Remove init callbak from command/processor.c
Remove init callback from compositor object subtypes

Remove init callback from buffer.c, frame.c, image.c, cursor.c,
framebuffer_device.c, monitor.c and monitor_mode.c
Remove init callback from compositor/wayland subtypes
Remove init callback from tests

Remove init callback form attribute_test.c and ws_set/test.c
Merge pull request #303 from xVin/remove_init_callback

Remove init callback
Fix declaration of ws_statement_append_indirect
Add more extensive docu to ws_command
Extend documentation of ws_argument