Move check for ACE Hash_Map in FindACE
Get rid of the check for ACE_String_Base_Const::size_type

Since we dropped ACE strings, this is no longer needed.

Also drop YarpCheckTypeSize, that diverged a lot from CMake original
file, and it is no longer used.
Get rid of YarpAceCheck

Now ACE is handled almost as any other dependency
Enable testing only when required
Change type from int to nite::SkeletonState to all getSkeletonState(int) methods
Test output
Quit OpenNI2DeviceServer if sensor cannot be found or cannot be initialized
Remove bool argument from updateInterface() (obsolete concept from OpenNIv1)