[PLAT-6604] coupon definitions and derivatives
[PLAT-6614] Pricing methods for new coupon definitions
[PLAT-6604] Fixing accrual factors added to definitions and derivatives
[PLAT-6604] Changed coupon name. Added amoutn accrued.
[PLAT-6604] Merge continued.
[PLAT-6604] Added toDerivative with time series
[PLAT-6604] Corrected toDerivative for CouponIborAverageFixingDatesDefinition to include the case where the fixing is on the reference date but not available yet. (Yuki)
[PLAT-6614] Pricing method for average coupon
[PLAT-6604] Changed name of methods in visitors for derivatives
[PLAT-6604] Changed name of methods in visitors for definitions
[PLAT-6604] Corrected date logic for CouponIborAverageCompounding
[PLAT-6604] Corrected date logic for CouponIborFlatCompounding
[PLAT-6614] Implemented pricing methods for average coupons
[PLAT-6604] Changed coupon ibor average compounding to allow sub-periods with different length. (Yuki)
[PLAT-6614] Extended tests for pv calculators
[PLAT-6614] Supported different number of fixing

Also added examples to unit tests for toDerivative and pricing methods.
[PLAT-6604] Changed varibale names to coherent names conventions. Added Javadoc. Corrected investment factor to start at 1.0 (instead of 0.0).
[PLAT-6604] Added javadoc and clean code for Ibor average with flat compounding. Clean AD code for curve sensitivity. (Yuki)
Added worked-out example of algorithmic differention curve senstivity computation for a swap (used in documentation).