added docs for distribution crowdsales

contracts/crowdsale/distribution/PostDeliveryCrowdsale.sol

@@ -4,6 +4,10 @@ import "../validation/TimedCrowdsale.sol";
 import "../../token/ERC20/ERC20.sol";
 import "../../math/SafeMath.sol";
 
+/**
+ * @title PostDeliveryCrowdsale
+ * @dev Crowdsale that locks funds from withdrawal until it ends
+ */
 contract PostDeliveryCrowdsale is TimedCrowdsale {
   using SafeMath for uint256;
 
@@ -13,6 +17,9 @@ contract PostDeliveryCrowdsale is TimedCrowdsale {
     promises[_beneficiary] = promises[_beneficiary].add(_tokenAmount);
   }
 
+  /**
+   * @dev Withdraw tokens only after crowdsale ends
+   */
   function withdrawTokens() public {
     require(hasExpired());
     uint256 amount = promises[msg.sender];

contracts/crowdsale/distribution/RefundableCrowdsale.sol

@@ -21,26 +21,37 @@ contract RefundableCrowdsale is FinalizableCrowdsale {
   // refund vault used to hold funds while crowdsale is running
   RefundVault public vault;
 
+  /**
+   * @param _goal Funding goal
+   * @param _vault Refund vault to temporarily store funds
+   */
   function RefundableCrowdsale(uint256 _goal, RefundVault _vault) public {
     require(_goal > 0);
     require(_vault != address(0));
     goal = _goal;
     vault = _vault;
   }
 
-  // if crowdsale is unsuccessful, investors can claim refunds here
+  /**
+   * @dev Investors can claim refunds here if crowdsale is unsuccessful
+   */
   function claimRefund() public {
     require(isFinalized);
     require(!goalReached());
 
     vault.refund(msg.sender);
   }
 
+  /**
+   * @return Whether funding goal was reached
+   */
   function goalReached() public view returns (bool) {
     return weiRaised >= goal;
   }
 
-  // vault finalization task, called when owner calls finalize()
+  /**
+   * @dev vault finalization task, called when owner calls finalize()
+   */
   function finalization() internal {
     if (goalReached()) {
       vault.close();
@@ -51,9 +62,9 @@ contract RefundableCrowdsale is FinalizableCrowdsale {
     super.finalization();
   }
 
-  // We're overriding the fund forwarding from Crowdsale.
-  // In addition to sending the funds, we want to call
-  // the RefundVault deposit function
+  /**
+   * @dev Overrides Crowdsale fund forwarding. In addition to sending the funds, we call the RefundVault deposit function
+   */
   function _forwardFunds() internal {
     vault.deposit.value(msg.value)(msg.sender);
   }

contracts/crowdsale/distribution/utils/RefundVault.sol

@@ -23,12 +23,18 @@ contract RefundVault is Ownable {
   event RefundsEnabled();
   event Refunded(address indexed beneficiary, uint256 weiAmount);
 
+  /**
+   * @param _wallet Vault address
+   */
   function RefundVault(address _wallet) public {
     require(_wallet != address(0));
     wallet = _wallet;
     state = State.Active;
   }
 
+  /**
+   * @param investor Investor address
+   */
   function deposit(address investor) onlyOwner public payable {
     require(state == State.Active);
     deposited[investor] = deposited[investor].add(msg.value);
@@ -47,6 +53,9 @@ contract RefundVault is Ownable {
     RefundsEnabled();
   }
 
+  /**
+   * @param investor Investor address
+   */
   function refund(address investor) public {
     require(state == State.Refunding);
     uint256 depositedValue = deposited[investor];