Calculates WAL of MtgCashFlows.

WAL and Delinquencies printed in output.
Closes #154
Implemented scaling method in generic cash flow.

Relates to #156
Scaled Cash flow method implemented and used.

Closes #156
Maturity Extension and Starting Haircut implemented as loans properties.

Fixed bug in loading extra properties.
Closes #150
Implemented PurchasePrice and DiscountLimit properties for loans to carry Discount Obligations at purchase price in OC test.

Closes #126
Implemented PrepaymentFee property for loans to deal with early redemption fees.

Fixed bug in loans day count conventions anchor date.
Relates to #157
Relates to #144
Prepayment fees can now be allocated via the waterfall, reinvestment test moved back to its own step even though its functionality is identical to an OC test.

Closes #157
Closes #153
Small functionality bugfix
Day count convention for loans moved to property.

Closes #161
.clom file is now used if no .clo is available and .clo is deleted on exit

Closes #152
Merge branch 'Development'