Restructure abe into modules

[newsch]

In the interest of addressing some issues/ideas that have risen up in the past couple weeks, mainly:

• structuring the project in an organized and logical way to encourage contributions and development from Olin students with a variety of programming/Python experience
• implementing unit tests for more of the project (started with Get testing framework in place #62)
• using the same database connection across resource models
• implementing sockets for event creation/deletion for f-board integration
• implementing Sphinx and Read the Docs for documentation similar to the Olin API
• the ability to add additional features/endpoints and new mongoengine document models to ABE, like /files/ as mentioned in Add ability to attach files to events #52

It seems that we've reached the comfortable limit of a flat project structure - I recently rearranged the project files in #44 based on the guidelines from The Hitchhiker's Guide to Python. Looking at the Olin API's folder structure, I think that splitting up document_models.py and resource_models.py would be a nice first step. After that helpers.py needs to be pulled apart and reorganized - I'm still not sure what the best way to structure it would be.

Some resources to help with Flask, sockets, and celery along the way:

• http://flask.pocoo.org/docs/0.12/patterns/appfactories/#app-factories
• https://stackoverflow.com/questions/13284858/how-to-share-the-global-app-object-in-flask
• http://flask.pocoo.org/docs/0.12/blueprints/
• http://flask.pocoo.org/docs/0.12/api/#flask.current_app
• https://gist.github.com/jzempel/3201722

I'm proposing a project structure similar to this:

.
├── abe
│   ├── __init__.py
│   ├── app.py
│   ├── database
│   │   ├── __init__.py
│   │   ├── connection.py
│   │   ├── mongo_config_sample.py
│   │   └── mongo_config.py
│   ├── resources
│   │   ├── __init__.py
│   │   ├── event_model.py
│   │   └── label_model.py
│   ├── helpers
│   │   ├── __init__.py
│   │   ├── postdeploy.py
│   │   ├── pr-predestroy.py
│   │   ├── sample_data.py
│   │   ├── mongo_helpers.py
│   │   └── ical_helpers.py
│   ├── documents
│   │   ├── __init__.py
│   │   ├── event_document.py
│   │   └── label_document.py
│   └── templates
│       ├── add_event.html
│       ├── add_label.html
│       └── splash.html
└── tests
│   ├── __init__.py
│   ├── context.py
│   └── test.py
├── docs
│   └── [documentation stuff]
├── app.json
├── .gitignore
├── LICENSE
├── Procfile
├── README.md
├── requirements.txt
├── run.py
└── runtime.txt

[Elepert]

Breaking up helpers.py into multiple helper functions is taken care of with #71
Greater restructuring with implementing document and resource model folders was taken care of with #68

[newsch]

As part of this, @songbird175 and I are working on a system diagram for ABE with #144.