src-tree cleanup: separate surfaces from libraries

libardourcp and now libardour_midisurface are not control
surfaces, but helper libraries for those.
They need to be deployed to the library folder (shared between
ctrl surfaces) and not scanned as ctrl surfaces at runtime.

libs/surfaces/wscript

@@ -20,8 +20,6 @@ top = '.'
 out = 'build'
 
 children = [
-    'control_protocol',
-    'midi_surface',
     'faderport',
     'faderport8',
     'cc121',
@@ -82,8 +80,6 @@ def configure(conf):
         sub_config_and_use(conf, i)
 
 def build(bld):
-    bld.recurse('control_protocol')
-    bld.recurse('midi_surface')
     bld.recurse('generic_midi')
     bld.recurse('faderport')
     bld.recurse('faderport8')