Docs: docstrings updates to room acoustics module
Move constants into module namespace

These constants are commonly usable.
Docs: docstrings updates to reflection, turbulence, octave and power.
Docs: new structure
Merge pull request #16 from FRidh/docs

Docs: new structure and updated docstrings.
Merge pull request #17 from FRidh/bands

Move constants into module namespace