Parser & Lexer Progress

- Corrected a lexing mistake for ATX tokens;
  One or more `=`, not four or more `=`. See
  `LexEnumBlock.js` for details.

- Added `shiftUntilPast()` to the base Parser.
  This method skips lexical tokens until it
  meets one that passes the check, then shifts
  past that token.

  This method is similar to `shiftUntil()`
  except it also jumps past the token that passes
  the check.

  See: `ParserBase.js`

- General progression with the block-level parser.