backport: Deal with Autoconf 2.62's semantic change in m4_append.

2008-03-16  Ralf Wildenhues <Ralf.Wildenhues@gmx.de>

	Backport from upstream Libtool:
	
	2007-10-12  Eric Blake  <ebb9@byu.net>
	
	Deal with Autoconf 2.62's semantic change in m4_append.
	* ltsugar.m4 (lt_append): Replace broken versions of
	m4_append.
	(lt_if_append_uniq): Don't require separator to be overquoted,
	and avoid broken m4_append.
	(lt_dict_add): Fix typo.
	* libtool.m4 (_LT_DECL): Don't overquote separator.

From-SVN: r133267