Add TokenTimelock#release function that anyone can call

Fix references to SafeMath in crowdsale contracts

Move SafeMath and create Math library for assorted operations

Add Crowdsale contracts

Added new test for a day passed scenario to the DayLimit contract

Add a TokenTimelock contract

fix(token): typo in documentation

it is superseded by the new crowdsale contracts

includes fix to MultisigWallet test because bigger balances result in
floating point errors (see #204)

Implemantation -> Implementation

change inheritance order for StandardToken and PausableToken

Remove all checks for short address attack

Fix typo in StandardToken allowance documentation

Removes install script