get rid of old parser (with separate tokenization, ast-parsing stages), replacing with combined parser which produces a concrete parse tree, plus a phase for converting into an AST
get rid of unnecessary tests and rearrange
parser:  added error reporting

tests:  test tokenizer, munching, context-free parsing, and error reporting

remove unneeded tests

maybeerror: inequality test was wrong
unit tests for ast builder; standardize error reporting somewhat
move tests into main nmrpystar src directory, and use only relative imports to get the modules so that outside dependencies aren't accidentally hit
fix the spec:
 - single quotes are special characters -- they can't begin
   unquoted values
 - newlines are not allowed in single- or double-quoted strings
 - double-quoted strings may contain double quotes, if they're not
   followed by whitespace

add these features to the implementation, and error reporting
  for newlines and missing close quotes

add tests for these features, and for error reporting

also:  add some tests for parsing data blocks
grammar specification:  use local rules to clarify
simplify grammar:  'newlines' token is unnecessary; fold in 'special' rule as local because it's only used in one other place
semicolon-delimited strings:
 - fix grammar: they must be preceded by newline
 - tests and implementation follow suit

semicolon-leading-unquoted values:
 - may be opened by semicolon
 - opening ; may be preceded by newline, if no closing newline/;
   sequence is found
test script:  verbose output
changes:
 - add 'global_' keyword
 - make keywords case-insensitive
 - allow unquoted values to start with 'stop_', 'loop_', and 'global_' if
   they're followed by more characters
 - allow 'data_' as an unquoted value

add these changes to spec, implementation, and tests

also alpha-substitute a few instances of 'input' as a variable
  name, since it's shadowing the built-in