Suppression of warnings

OffsetOf: use of static_cast
Updatable: API and virtual destructor
Drawable: virtual destructor
Vector: std::abs should be "the" abs.
AbstractClass: API
+Updatable: Like for others abstracts
Buffer: nullptr for pointer to function.
Image: wasn't returning a vector.

Former-commit-id: 57e0009286a02b9e3b0b81945e500d7d9e466ae2

src/Nazara/Utility/Buffer.cpp

@@ -297,4 +297,4 @@ void NzBuffer::Uninitialize()
 	std::memset(s_bufferFactories, 0, (nzDataStorage_Max+1)*sizeof(NzBuffer::BufferFactory));
 }
 
-NzBuffer::BufferFactory NzBuffer::s_bufferFactories[nzDataStorage_Max+1] = {0};
+NzBuffer::BufferFactory NzBuffer::s_bufferFactories[nzDataStorage_Max+1] = {nullptr};

src/Nazara/Utility/Image.cpp

@@ -809,7 +809,7 @@ NzVector3ui NzImage::GetSize(nzUInt8 level) const
 	if (level >= m_sharedImage->levelCount)
 	{
 		NazaraError("Level out of bounds (" + NzString::Number(level) + " >= " + NzString::Number(m_sharedImage->levelCount) + ')');
-		return 0;
+		return NzVector3ui::Zero();
 	}
 	#endif