Reorganise entries and use LFS for zipped files

[fepegar]

• [x] Each model zoo entry should have its own directory
• [x] The models weights can be in the corresponding directory and stored with Git LFS

[fepegar]

@dzhoshkun, can you please give @wyli and me rights for this?

[dzhoshkun]

I've made you both admins on this repo now. You should've received a notification/invitation by email.

[wyli]

implemented at https://github.com/NifTK/NiftyNetModelZoo/tree/5-reorganising-with-lfs