Added tests for LST and SAV directives.

Also fixed bugs that this uncovered:
* Just ignore LST directives in the first pass of the assembler.
* The SAV directive was saving a binary file with two bytes of zeroes
  instead of the expected 0x69 0x20.  It turns out that the call to
  BSAV was using the first 1k above HIMEM (where I was storing machine
  code) as scratch space for file buffers, etc.  I now set HIMEM to the
  same address as before but I start the programCounter 1k above that
  reserve value.
* I was also invoking the BSAV command incorrectly which resulted in a
  syntax error.  I added the required commas to fix that bug.
* Updated matchOperatorTo65c02Instruction() to return immediately if it
  finds a match since I don't need to worry about aligning the DATA
  pointer to the beginning of the directive table if the find has
  already happened in the instruction table.