Merge branch 'master' into windows

diff --cc gtk2_ardour/ardour_ui.cc
Simple merge

diff --cc gtk2_ardour/ardour_ui_dialogs.cc
Simple merge

diff --cc gtk2_ardour/export_dialog.cc
Simple merge

diff --cc gtk2_ardour/processor_box.cc
Simple merge

diff --cc gtk2_ardour/route_time_axis.cc
Simple merge

diff --cc libs/ardour/lv2_plugin.cc
Simple merge