Create an arena allocator with hugepages and locked memory

[Morcules]

• Allocate huge pages at swiftnet_initialize (2048Kb)
• Dynamically allocate more huge pages as arena grows (start with 20Mb)
• Get hugepage ptr using mmap
• Lock the memory using mlock
• Replace every single malloc with arena allocation and also make datatype_allocator use the arena
• Make swiftnet_create_buffer use the arena