Integrate additional modules into Occiput

[mscipio]

Integration of the following external libraries into Occiput:

• NiftyPy
• Interfile
• iLang
• PetLink
• SimpleWrap
• DisplayNode (???)

An example of doing this while keeping these submodules independent from Occiput can be seen here: occiput-suite.

However, this required many changes to the setup.py file and the organization of the whole module remain a bit chaotic, and hard to maintain. Since most of these (sub)modules are usable only through Occiput, it may be reasonable to completely integrate most of them.

[mscipio]

Update --> latest commit on branch feature-2-integrate-niftypy

1. Integrated NiftyPy into occiput (now we have occiput.Functional.NiftyRec and occiput.Functional.NiftyReg);

2. Getting rid of NiftyPy_wrap.py in occiput.Core as it was redundant;

3. moving some of the functions defined in NiftyPy_wrap as wrapper of NyftyRec functions into occiput.Core.Core.py;

4. Integrating Interfile into occiput (it can be found at occiput.Core.Interfile);

5. Added test_interfile/ subfolder in occiput.test;

6. Added data folder occiput.Data.interfile_examples containing data required by occiput.test.test_interfile;\

7. Started translating imports from global to relative for SO consistency, and better management of dependencies;

8. Added file occiput.Reconstruction.PET.PET_profiler.py as it was missing [in the future outdated version of (at least) PET.py? #4 we will need to check with which version of PET.py we are currently working, as the fact the profiler is not used makes me think that this is not the latest version available]