initial commit:

- r6rs docs
- Makefile
- token linkage unit tests
adding major components and test outlines
tidying up testing framework, adding tests for all modules, cleaning makefile
small cleanup of makefile
added failing tests for parse
tracked down segfualt; added plot_ prefix to prevent my 'read' from conflicting with read(2)
naive read implementation added
initial layout of parsing structures
starting to flesh out parse and parse_sexpr
environment starting, added fixme notes to variable
making variable hold value rather than pointer
fleshing out parsing a bit more
tidying up documentation
the great rearranging
tests passing, parse rewritten to actually do work
removing unneeded allocations, pushing allocations further up the chain
added in 'hard' parser test, encapsulating debugging callocs, adding FIXMEs
making test output more helpful
now correctly parsing values (symbols and numbers) and testing for their correct parsing (currently only in test_parse_expr)
added new testing macros, added hash datatype and skeleton, added unit tests for hash