use scheme for setting paper variables
get paper variable values dynamically from output-def
update documentation to match new paper variable inputs
better approach to single number input, and add stretchability defaults
refactor, inputs now match LilyPond property names, lists instead of alists in input
Fix README formatting
one more minor formatting of README
update example file
Merge pull request #55 from PaulMorris/vert-scaling

Vert scaling