Update support for GNU BUILD notes so that version notes can contain extra informatio...

Update support for GNU BUILD notes so that version notes can contain extra information, and stack protection notes can contain numeric values.

	* readelf.c (print_gnu_build_attribute_name): Allow stack
	protection notes to contain numeric values.  Use a colon rather
	than a space to separate a string name from its values.  Decode
	the numeric value of a stack protection note.
	* objcopy.c (merge_gnu_build_notes): Allow version notes to
	contain extra text after the protocol version number.