register items with FML so they survive through a 1.7 upgrade

This should remove the following "errors" from the FML logfile, as well as allow the items to potentially transition to 1.7

2013-12-04 00:33:54 [SEVERE] [ForgeModLoader] Found anonymous item of class codechicken.microblock.ItemMicroPart with ID 25131 owned by mod ForgeMicroblock, this item will NOT survive a 1.7 upgrade!
2013-12-04 00:33:54 [SEVERE] [ForgeModLoader] Found anonymous item of class codechicken.microblock.ItemSaw with ID 25132 owned by mod ForgeMicroblock, this item will NOT survive a 1.7 upgrade!
2013-12-04 00:33:54 [SEVERE] [ForgeModLoader] Found anonymous item of class codechicken.microblock.ItemSaw with ID 25133 owned by mod ForgeMicroblock, this item will NOT survive a 1.7 upgrade!
2013-12-04 00:33:54 [SEVERE] [ForgeModLoader] Found anonymous item of class codechicken.microblock.ItemSaw with ID 25134 owned by mod ForgeMicroblock, this item will NOT survive a 1.7 upgrade!