merge from master

diff --cc gtk2_ardour/ardour_ui.cc
Simple merge

diff --cc gtk2_ardour/ardour_ui.h
Simple merge

diff --cc gtk2_ardour/editor_drag.cc
Simple merge

diff --cc gtk2_ardour/editor_ops.cc
Simple merge

diff --cc gtk2_ardour/editor_routes.cc
Simple merge

diff --cc gtk2_ardour/editor_selection.cc
Simple merge

diff --cc gtk2_ardour/generic_pluginui.cc
Simple merge

diff --cc gtk2_ardour/rc_option_editor.cc
Simple merge

diff --cc libs/ardour/ardour/rc_configuration_vars.h
Simple merge

diff --cc libs/ardour/wscript
Simple merge

diff --cc wscript
index b786136f6ff00abd5c741b983d8cb8291c8a1acb,3d016326d5901266d80d06817483f08dd318d675..1252096bda0c4d0567984ea6d9c86e2f9790d7b4
--- 1/wscript
--- 2/wscript
+++ b/wscript
@@@ -35,7 -35,7 +35,8 @@@ children = 
          'libs/gtkmm2ext',
          'libs/clearlooks-newer',
          'libs/audiographer',
 +        'libs/canvas',
+         'libs/plugins/reasonablesynth.lv2',
          'gtk2_ardour',
          'export',
          'midi_maps',