* keymap.c (describe_buffer_bindings): Adjust key_heading to match

* keymap.c (describe_buffer_bindings): Adjust key_heading to match
	the format used by describe_map_tree.  Also, don't reprint the
	"key    binding" header above the global bindings if we've already
	printed it for the local bindings; it's clear enough that the
	columns mean the same thing as above.

	* keymap.c (describe_buffer_bindings): Declare buf and bufend...

	* keymap.c (describe_buffer_bindings): Set the current buffer to
	descbuf before calling current_minor_maps; that function's value
	depends on the values of buffer-local variables.  Don't set the
	current buffer to Vstandard_output until afterwards.

	* keymap.c (describe_buffer_bindings): If
	Vkeyboard_translate_table is in effect, describe its effects.