* src/vteapp.c, python/vte-demo.py: allow specifying the scrollback buffer size.
* src/vte.c: if we don't have <wchar.h>, typedef wchar_t as a gunichar, not a
	long.
* src/buffer.c, src/buffer.h: add.
* src/interpret.c, src/vte.c: use _vte_buffer structures instead of char arrays
	with separate lengths.  Use a scratch buffer for holding the results of
	conversions.
* src/vte.c: separate the pango and pangox drawing paths so that they're easier
	to tweak and compare to each other.
* src/vte.c: ditch the smooth scrolling change, which won't work right anyway
	(expose events don't get processed until after we finish processing a
	chunk of data unless we explicitly request it, so using a bbox is both
	simpler and faster).  Use a mask when creating the cursor we use for
	hiding the cursor.
* vte.spec, gnome-pty-helper/Makefile.am: install gnome-pty-helper into the
	libexecdir, not pkglibdir (#95085).
* src/vte.c: obey smooth/jump scrolling options, default is jump scroll.
* src/vte.c (vte_font_match): Fix over-aggressive Xft => Fc conversion - need
	to call XftDefaultSubstitute to pick up Xft X resources, not
	FcDefaultSubstitute.  From otaylor.