Merge pull request #1 from michelk/master

Aquaveo-SMS-2dm reader and writer
Refactored into multiple files. Vertex and Face immutable types replace tuples.
Removed unused geometry.jl.
Tweaked readme.
Tweaked readme, again.
Fixed merge. Added smoke test.
Merge pull request #1 from twadleigh/master

New types for face and vertex, plus refactoring. Add a test?