* src/vte.c(vte_terminal_get_text_maybe_wrapped): add a parameter to control
	whether or not trailing whitespace is trimmed (padraig.obriain,
	#141148).
* src/vte.c,src/vte.h(vte_terminal_get_text_include_trailing_spaces): add as a
	wrapper for the new vte_terminal_get_text_maybe_wrapped()
	(padraig.obriain, #141148).
* src/vteaccess.c(vte_terminal_accessible_update_private_d): use
	vte_terminal_get_text_include_trailing_spaces to ensure that we get
	trailing spaces (padraig.obriain, #141148).
* src/vte.c(vte_terminal_insert_char): clean up some autowrap stuff.