* Basic idea

* Fine tuning idea

* Add comments / tidy up Crowdsale base class

* fixed TimedCrowdsale constructor

* added simple crowdsale test

* added HODL directory under home to store unused contracts. ugly hack to solve Crowdsale selection in tests, better way?

* Capped no longer inherits from Timed, added capReached() method (replacing hasEnded())

* added SafeMath in TimedCrowdsale for safety, CHECK whether it is inherited from Crowdsale

* several fixes related to separating Capped from Timed. functions renamed, mocks changed. Capped tests passing

* added TimedCrowdsaleImpl.sol, TimedCrowdsale tests, passed

* added Whitelisted implementation and test, passed.

* removed unnecessary super constructor call in WhitelistedCrowdsale, removed unused dependencies in tests

* renamed UserCappedCrowdsale to IndividuallyCappedCrowdsale, implemented IndividuallyCappedCrowdsaleImpl.sol and corresponding tests, passed.

* homogeneized use of using SafeMath for uint256 across validation crowdsales. checked that it IS indeed inherited, but leaving it there as per Frans suggestion.

* adding questions.md where I track questions, bugs and progress

* modified VariablePriceCrowdsale, added Impl.

* finished VariablePrice, fixed sign, added test, passing.

* changed VariablePrice to IncreasingPrice, added corresponding require()

* MintedCrowdsale done, mock implemented, test passing

* PremintedCrowdsale done, mocks, tests passing

* checked FinalizableCrowdsale

* PostDeliveryCrowdsale done, mock, tests passing.

* RefundableCrowdsale done. Detached Vault. modified mock and test, passing

* renamed crowdsale-refactor to crowdsale in contracts and test

* deleted HODL old contracts

* polished variable names in tests

* fixed typos and removed comments in tests

* Renamed 'crowdsale-refactor' to 'crowdsale' in all imports

* Fix minor param naming issues in Crowdsale functions and added documentation to Crowdsale.sol

* Added documentation to Crowdsale extensions

* removed residual comments and progress tracking files

* added docs for validation crowdsales

* Made user promises in PostDeliveryCrowdsale public so that users can query their promised token balance.

* added docs for distribution crowdsales

* renamed PremintedCrowdsale to AllowanceCrowdsale

* added allowance check function and corresponding test. fixed filename in AllowanceCrowdsale mock.

* spilt Crowdsale _postValidatePurchase in _postValidatePurchase and _updatePurchasingState. changed IndividuallyCappedCrowdsale accordingly.

* polished tests for linter, salve Travis

* polished IncreasingPriceCrowdsale.sol for linter.

* renamed and polished for linter WhitelistedCrowdsale test.

* fixed indentation in IncreasingPriceCrowdsaleImpl.sol for linter

* fixed ignoring token.mint return value in MintedCrowdsale.sol

* expanded docs throughout, fixed minor issues

* extended test coverage for IndividuallyCappedCrowdsale

* Extended WhitelistedCrwodsale test coverage

* roll back decoupling of RefundVault in RefundableCrowdsale

* moved cap exceedance checks in Capped and IndividuallyCapped crowdsales to _preValidatePurchase to save gas

* revert name change, IndividuallyCapped to UserCapped

* extended docs.

* added crowd whitelisting with tests

* added group capping, plus tests

* added modifiers in TimedCrowdsale and WhitelistedCrowdsale

* polished tests for linter

* moved check of whitelisted to modifier, mainly for testing coverage

* fixed minor ordering/polishingafter review

* modified TimedCrowdsale modifier/constructor ordering

* unchanged truffle-config.js

* changed indentation of visibility modifier in mocks

* changed naming of modifier and function to use Open/Closed for TimedCrowdsale

* changed ordering of constructor calls in SampleCrowdsale

* changed startTime and endTime to openingTime and closingTime throughout

* fixed exceeding line lenght for linter

* renamed _emitTokens to _deliverTokens

* renamed addCrowdToWhitelist to addManyToWhitelist

* renamed UserCappedCrowdsale to IndividuallyCappedCrowdsale