* defs.h, gdbtk.c (gdbtk_fputs), main.c (gdb_fputs), top.c: Add stream arg

	* defs.h, gdbtk.c (gdbtk_fputs), main.c (gdb_fputs), top.c:  Add stream arg
	to fputs_unfiltered_hook.  Differentiate stdout from stderr when
	passing text into tcl land.
	* defs.h, top.c, utils.c (error):  Add error_hook.
	* gdbtk.c:  Improve mechanism for capturing output values.
	* (full_filename):  Remove.
	* (gdb_cmd call_wrapper gdbtk_init):  Protect all calls from tcl
	land with call_wrapper.  This prevents longjmps (usually via
	error()) from jumping out of tcl/tk and leaving things in an
	indeterminate state.
	* gdbtk.tcl:  New view option to disable line numbers.  Put catch
	around most uses of gdb_cmd.  Add update button to reg config
	window.  Stop doing immediate updates when selecting registers.
	Change register view values into checkbuttons.