Fixed Starter Bugs

Very simple kinks worked out.  Missing commas on ADDI, SLTI, ADDIU, and
BNE, .  Apparently SLL, SRL, and SRA require hash tags.  SRL is once
mistaken for a NOP (but I don't see how this SRL is considered valid
code since the target register is R0).  Lastly, BLEZ failed its
negativity check.