* NEWS: Mention new python command class gdb.COMMAND_USER.

	* NEWS: Mention new python command class gdb.COMMAND_USER.
	* cli/cli-cmds.c (show_user): Print error when used on a python
	command.
	(init_cli_cmds): Update documentation strings for "show user" and
	"set/show max-user-call-depth" to clarify that it does not apply to
	python commands.
	* python/py-cmd.c (cmdpy_init): Treat class_user as a valid class in
	error check.
	(gdbpy_initialize_commands): Add COMMAND_USER as a constant in
	gdb python api.
	* top.c (execute_command): Only execute a user-defined command as a
	legacy macro if c->user_commands is set.

	doc/
	* gdb.texinfo (Commands In Python): Put example python macro in
	COMMAND_USER category rather than COMMAND_OBSCURE.
	Document gdb.COMMAND_USER.
	(User-defined Commands): Update documentation to clarify
	"set/show max-user-call-depth" and "show user" don't apply to python
	commands.  Update documentation to clarify "help user-defined" may
	also include python commands defined as COMMAND_USER.

	testsuite/
	* gdb.python/py-cmd.exp: Add test to verify that python commands can
	be put in the user-defined category and that the commands appear in
	"help user-defined".