Changes

Have also to fix theses "Bad Command" responses from fdc (it seems that when you don't reach a track, you have to send back the current track instead of this "Bad Command" signal). Test : 30YMD demo, "disk change" message not running correctly, "another disk inserted" is not detected in this demo.

* 27FAIL01/29FAIL01 : read_track6/read_track10 - very big sector size counter not implemented (more than 512B)

* 3DFAIL/45FREEZE : read_data_ov/test_write_ov - using flag simpleDSK.IS_ARNOLDEMU_TESTBENCH=false this test will fail/freeze in final compilation. will not be implemented (does slow down some demos : 30YMD/Batman)