Add struct.py mirroring C struct declarations.
Add struct.py mirroring C struct declarations.

- C structs in rpacket.h, storage.h and rk_mt.h
  have been replicated in struct.py as per the
  design technique while using C types. These
  structs will now be used to pass in wrapped C
  methods.

Tobychev/tardis,orbitfold/tardis,Tobychev/tardis,kaushik94/tardis,Tobychev/tardis,kaushik94/tardis,orbitfold/tardis,kaushik94/tardis,orbitfold/tardis,orbitfold/tardis,kaushik94/tardis