Converted source to Literate Kal

The code is mostly untouched except for some cleanup and minor
changes to use new syntax. The big change is the new wealth of
documentation.

gh-117
fixes to literate translation

we don't need to deal with ###s after #s, they are ignored anyway.
only detect code blocks with a preceeding newline
fix class definitions to only accept Variables as names rather than IDENTIFIERs