This submission adds the While construct to the interpreter. Some small changes were made to the parser to differentiate it from an 'if' statement. Commenting out the 'moveAbsolute()' in the second While statement causes moveAbsolute() to be called with the seconds parameter of 7, 9 and then 11 after While is existed.
Testing the output of log.txt is only preliminary. No obvious mistakes, but please let me know.

To do: Want to make nodeTemporary symbols available again after use by changing their type to nodeAvailable.