* annotate.c, breakpoint.c, defs.h, gdbtk.c, top.c: Replace

	* annotate.c, breakpoint.c, defs.h, gdbtk.c, top.c:  Replace
	enable/disable_breakpoint_hook with modify_breakpoint_hook.
	* gdbtk.c:  General cleanups, get rid of unused variables.  Redo
	handling of stdout/stderr to just return output as the result of
	the tcl command that caused the output.  Cleanup -Wall stuff.
	* (breakpoint_notify):  Now returns just action and breakpoint
	number.
	* (gdb_get_breakpoint_list):  New routine.  Does the obvious.
	* (gdb_get_breakpoint_info):  Mostly derived from the old
	breakpoint_notify, but returns lots more info.
	* (dsprintf_append_element):  Helper routine, works like printf,
	but appends a tcl element onto the specified DString.  Good for
	building up lists as return values.
	* (gdbtk_enable/disable_breakpoint):  Go away.  Replaced with
	gdbtk_modify_breakpoint.
	* (*many routines*):  Use new result protocol.
	* (call_wrapper):  Make sure that recursive calls don't trash results.
	* gdbtk.tcl:  New windows, autocmd, and breakpoints.
	* (gdbtk_tcl_fputs):  Don't use $current_output_win redirection
	anymore.  It's not needed (in fact, this routine may not be needed
	anymore).
	* (gdbtk_tcl_breakpoint):  Change to reflect new breakpoint
	notification protocol.
	* (gdbtk_tcl_busy gdbtk_tcl_idle):  Straighten out buttons, remove
	catches.
	* (interactive_cmd):  Use this wrapper around button invocations
	of many commands.  This will catch errors and put the results into
	the command window.  It also updates all the other windows.
	* Also, change reliefs of most things to sunken.  This actually
	looks better.
	* (create_file_win):  Fix margin binding to allow breakpoints to
	work again.
	* (create_asm_win):  Use return value of gdb_disassemble instead
	of implicit I/O to the command window.
	* (create_command_window):  Use new result protocol to get output
	from commands.