[PLT-430] Added coupon ibor with fx reset: definition and derivative
[PLT-430] Implemented pv, sensitivity, fx exposure calculators
PLAT-6802 - Enhance performance of MasterHolidaySource
[PLT-430] Test for CouponIborFxReset and its definition class
[PLAT-6805] Adding support for Fixed/OIS swaps

Support for par rate calculation exists for all fixed-float swaps but
the converter from financial security to swap definition does not
process fixed-float swaps to a fixed-float swap definition if the index
is other than ibor.

This PLAT adds the support for swap with floating leg with OIS index.
[PLT-430] Tests for pv, sensitivity, currency exposure calculators

Reverted the change for coupon ibor spread calculator
[PLT-430] Added swap example
PLAT-6802 - Enhance performance of MasterHolidaySource

Fixup from PR
[PLT-430] Extended toDerivative test, added javadoc for individual tests

Also changed variable names for ibor index fixing
[PLT-430] Added a missing javadoc
PLT-451 - Remove use of convention and security source

Replaced with links so caching is applied correctly
Reformatted to match standards
[PLAT-6805] Downcasting ON coupons to generate fixed-float swap definition

Basically mimicking the same behavior as for ibor coupons
Update release notes
Update release notes
Bump version to 2.6.0-SNAPSHOT
PLT-451 - Remove use of convention and security source

Fixed tests
[PLAT-6805] Adding checks to handles cases with stubs and notional exchanges properly
PLT-451 - Remove use of convention and security source

Address review comments
[PLAT-6808] Correct missing accrued in AA coupons with spread.
PLT-451 - Remove use of convention and security source

Merge from develop