[Development] Renaming quint128

[Thiago Macieira]

I was working on extended integers and added qint128 and quint128 to qglobal.h 
(qtypes.h), but when I tried to rebuild all of Qt today, I found out that 
QtBluetooth has this in qbluetoothuuid.h:

struct quint128
{
    quint8 data[16];
};

And it's used in the API, with a constructor and a toUInt128(), but that's 
all. It's also not documented.

I'd like to move it away so I can add the proper integer.

There's a way to replace it without breaking BC or SC:
1) on 64-bit systems with GCC and Clang, use the actual integer type
2) everywhere else, use the the struct
3) for QtBluetooth's own build, add a removed_api.cpp that also #undef 
__SIZEOF_INT128__

It might be a good idea to move that backup definition to QtCore, so 
QtBluetooth isn't depending on just how qtypes.h does it.
-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Cloud Software Architect - Intel DCAI Cloud Engineering