* dbus/dbus-marshal.c (_dbus_marshal_validate_arg): fix to avoid
	calling _dbus_marshal_validate_arg() for every byte in a byte
	array, etc.

	* dbus/dbus-message-handler.c: use atomic reference counting to
	reduce number of locks slightly; the global lock in here sucks

	* dbus/dbus-connection.c
	(_dbus_connection_update_dispatch_status_and_unlock): variant of
	update_dispatch_status that can be called with lock held; then use
	in a couple places to reduce locking/unlocking
	(dbus_connection_send): hold the lock over the whole function
	instead of acquiring it twice.

	* dbus/dbus-timeout.c (_dbus_timeout_new): handle OOM

	* bus/connection.c (bus_connections_setup_connection): fix access
	to already-freed memory.

	* dbus/dbus-connection.c: keep a little cache of linked list
	nodes, to avoid using the global linked list alloc lock in the
	normal send-message case. Instead we just use the connection lock
	that we already have to take.

	* dbus/dbus-list.c (_dbus_list_find_last): new function

	* dbus/dbus-sysdeps.c (_dbus_atomic_inc, _dbus_atomic_dec):
	change to use a struct for the atomic type; fix docs,
	they return value before increment, not after increment.

	* dbus/dbus-string.c (_dbus_string_append_4_aligned)
	(_dbus_string_append_8_aligned): new functions to try to
	microoptimize this operation.
	(reallocate_for_length): break this out of set_length(), to
	improve profile info, and also so we can consider inlining the
	set_length() part.

	* dbus/dbus-message.c (dbus_message_new_empty_header): init data
	strings with some preallocation, cuts down on our calls to realloc
	a fair bit. Though if we can get the "move entire string to empty
	string" optimization below to kick in here, it would be better.

	* dbus/dbus-string.c (_dbus_string_move): just call
	_dbus_string_move_len
	(_dbus_string_move_len): add a special case for moving
	an entire string into an empty string; we can just
	swap the string data instead of doing any reallocs.
	(_dbus_string_init_preallocated): new function