waf: split copter and heli builds

this makes things less confusing for users

ArduCopter/wscript

@@ -47,7 +47,7 @@ def build(bld):
 
     bld.ap_program(
         program_name='arducopter-heli',
-        program_groups=['bin', 'copter'],
+        program_groups=['bin', 'heli'],
         use=vehicle + '_libs',
         defines=['FRAME_CONFIG=HELI_FRAME'],
         )

wscript

@@ -422,7 +422,7 @@ ardupilotwaf.build_command('check-all',
     doc='shortcut for `waf check --alltests`',
 )
 
-for name in ('antennatracker', 'copter', 'plane', 'rover', 'sub'):
+for name in ('antennatracker', 'copter', 'heli', 'plane', 'rover', 'sub'):
     ardupilotwaf.build_command(name,
         program_group_list=name,
         doc='builds %s programs' % name,