VPN performancev2

This version contains three major modifications to improve performance and reduce garbage

    - Recycling of objects through class.lua
    - Pre-boxing of ctypes in lib/protocol/datagram.lua and lib/protocol/header.lua
    - Usage of libpcap for efficient packet classification

The system still exhibits several "steady-state" modes differing in JIT characteristics (amount of code compiled/interpreted and amount of GC). The mode is usually selected right after start-up, but it is unclear what influences this decision. In a "good" run, the app achieves 100% JIT compilation according to the profiler. Performance has been tested up to 800kpps.