New commands "mt set per-command {space,time,symtab} {on,off}".

	New commands "mt set per-command {space,time,symtab} {on,off}".
	* NEWS: Add entry.
	* event-top.c: #include "maint.h".
	* main.c: #include "maint.h".
	* maint.c: #include <sys/time.h>, <time.h>, block.h, top.h,
	timeval-utils.h, maint.h, cli/cli-setshow.h.
	(per_command_time, per_command_space): New static globals.
	(per_command_symtab): New static global.
	(per_command_setlist, per_command_showlist): New static globals.
	(struct cmd_stats): Move here from utils.c.
	(set_per_command_time): Renamed from set_display_time in utils.c
	and moved here.  All callers updated.
	(set_per_command_space): Renamed from set_display_space in utils.c
	and moved here.  All callers updated.
	(count_symtabs_and_blocks): New function.
	(report_command_stats): Moved here from utils.c.  Add support for
	printing symtab stats.  Only print data if enabled before command
	executed.
	(make_command_stats_cleanup): Ditto.
	(sert_per_command_cmd, show_per_command_cmd): New functions.
	(_initialize_maint_cmds): Add new commands
	mt set per-command {space,time,symtab} {on,off}.
	* maint.h: New file.
	* top.c: #include "maint.h".
	* utils.c (reset_prompt_for_continue_wait_time): New function.
	(get_prompt_for_continue_wait_time): New function.
	* utils.h (reset_prompt_for_continue_wait_time): Declare
	(get_prompt_for_continue_wait_time): Declare.
	(make_command_stats_cleanup): Moved to maint.h.
	(set_display_time, set_display_space): Moved to maint.h and renamed
	to set_per_command_time, set_per_command_space.
	* cli/cli-setshow.c (parse_cli_boolean_value): Renamed from
	parse_binary_operation and made non-static.  Don't call error,
	just return an error marker.  All callers updated.
	* cli/cli-setshow.h (parse_cli_boolean_value): Declare.

	doc/
	* gdb.texinfo (Maintenance Commands): Add docs for
	"mt set per-command {space,time,symtab} {on,off}".

	testsuite/
	* gdb.base/maint.exp: Update tests for per-command stats.