Fixes: debbugs:19149

* gtkutil.c (gtk_adjustment_configure): Define for Gtk+ < 2.14.
(xg_set_toolkit_horizontal_scroll_bar_thumb): Remove wrong version
check for gtk_adjustment_configure (Bug#19149).
* tramp.texi (Remote processes): Let-bind environment variables to
`process-environment' when running `process-file' or `start-file-process'.