Fixed a bug in TaskFollow and TaskEscort

- In TaskFollow method, controllerId was renamed back to groupId. Did
this in all required functions in the Controllable.lua where this
mistake was made during renaming.
- In TaskFollow method, fixed the lastWptIndexFlag bug, which needs to
be set to false if lastWptIndex is not given. Did this fix also in
TaskEscort method.
- Made an additional test mission to demonstrate the TaskFollow API.

Moose Test Missions/Moose_Test_GROUP_TaskFollow/Moose_Test_GROUP_TaskFollow.lua

@@ -0,0 +1,24 @@
+
+--Create Spawn Groups
+local SpawnPlane1 = SPAWN:New("Plane 1")
+local SpawnPlane2 = SPAWN:New("Plane 2")
+
+--Spawn Groups into world
+local GroupPlane1 = SpawnPlane1:Spawn()
+--local GroupPlane1 = GROUP:FindByName( "Plane 1" )
+local GroupPlane2 = SpawnPlane2:Spawn()
+--local GroupPlane2 = GROUP:FindByName( "Plane 2" )
+
+--Create Task for plane2 (follow groupPlane1 at Vec3 offset) (Note: I think I need to be using controllers here)
+--i.e. cntrlPlane1 = groupPlane1.getController(groupPlane1)
+
+local PointVec3 = POINT_VEC3:New( 100, 0, -100 ) -- This is a Vec3 class.
+
+local FollowDCSTask = GroupPlane2:TaskFollow( GroupPlane1, PointVec3:GetVec3() )
+
+--Activate Task (Either PushTask/SetTask?)
+-- PushTask will push a task on the execution queue of the group.
+-- SetTask will delete all tasks from the current group queue, and executes this task.
+
+GroupPlane2:SetTask( FollowDCSTask, 1 )
+