clean some code and add comments

Src/Arranger/FOctreeArranger.hpp

Src/Components/FAbstractSerializable.hpp

Src/Components/FParticleType.hpp

Src/Containers/FAbstractBuffer.hpp

Src/Containers/FBlockAllocator.hpp

Src/Containers/FMpiBufferReader.hpp

Src/Containers/FMpiBufferWriter.hpp

Src/Containers/FTreeCoordinate.hpp

Src/Utils/FAlignedMemory.hpp