Renamed verybasic.rb to parser.rb, which is reflected in spec requires
Corrected name of parser_spec.rb
Split out stdin and stdout capture to a helper. Added full program tests.
Corrected skip_space to suck up all the white space, as was intended
Added FOR loop handling. Added whole program handling
Added more tests of expressions: precedence, assignment, and printing
Refactored term. do_print now expects eexpressions, rather than raw values.
Added a few specs, including exponents. Prepared for function testing.
Added power expressions.
Added trig, log, and rounding functions. PRECEDENCE IS INCORRECT AT PRESENT