* Add/update binary conversion functions to use `std::memcopy`
* Only GCC could actually optimize the custom code using bit operations
* Clang could only optimize the `getBytes()` functions
* MSVC could not optimize any of the functions
* The to…Int…() functions cannot be updated as they are `constexpr` (and
thus `std::memcopy` and `reinterpret_cast` cannot be used). So they stay
as-is and `toInt()` has been added instead
* The `BinaryReader` class has been updated to use the new `toInt()`
function
The detection for big endian seems to work. But the special
handling for big endian is wrong. Only without it tests pass
under ppc64. Tested with Tumbleweed ppc64 image ran within
qemu-system-ppc64.