Adding comments to user_logic AXI stuff...
Added user_logic_AXImasterTest.v. Haven't actually modified the exmaple code yet--need to remove software control reg writing part and just hardcode control registers to do a testcase on board.
Or perhaps better to use Modelsim first? can instantiate user_logic_AXItest module in testbench--> need to take out useless signals from user_logic.