Documentation overhaul

[Bradley Dice]

From our roadmap planning session, @vramasub and @bdice identified several ways to improve the documentation. Some of these are in progress.

• Fix module docstrings
• Fix all class/function docstrings
  • Convert existing to Google style
  • Seek input / revision from module authors where available
• Development Guide
  • Add more detailed information on the standards for memory management
  • Precisely detail the use of the different languages
  • Discuss appropriate docstrings
• Add licenses for other software that we're using e.g. Eigen, TBB
• Create a thorough dependency list

[Vyas Ramasubramani]

Most of this was addressed by Pull Request #180. The outstanding items are:

• Revise content for modules where authors are available for improvement.
• Standardize dependency list (once the dust has settled on all our revisions).
• Write out memory management rules once we have standardized them.