transferInternal() is not verifying token transfers anymore, only tra…

…nsfer() and transferFrom() does

This fundamentally changes how forceTransfer(), issueTokens() and burnTokens()
behave: they are not dependant anymore on transactionVerifier.

SecurityToken checkpointing is now manual, and not relying on block n…

…umbers anymore

First version of TM-01 as used with TokenMarket Ltd's A shares at 0x1…

…a7918b6AFaA8D3321E49FCc64B02FD8be1225fa