Added Sheet class and first sheet test.
Divided sheet functinos.
Added functions for finding ledger lines
Added files with altered names.
Got a working version of s.get_staffs_positions()
Added Zach's note class.
Made minor corrections to Note class.

Added initializer, removed default values, replaced if-statement with
dictionary.
Stubbed functino for getting note images
Added init for packaging.
Merge branch 'master' of https://github.com/evanandrewrose/sight-parse
Added code to generate note image files.
Fixed dumb instantiation example.