Tidying up hydro_forces (#44)

* cleaning up TestHydro

Cleaning up:

- AddWaves
- GetVelHistory
- SetVelHistory
- ComputeForceHydrostatics

* cleaning up convolution integral

* tidy up TestHydro::GetRIRFval and TestHydro::ComputeForceWaves

* tidy TestHydro::CoordinateFuncForBody

* create constants for number of dofs, tidy up TestHydro

* tidy up hydro_forces.h

Author: dav-og

.gitignore

@@ -47,4 +47,6 @@ _build/
 build/
 data/
 demos/F3OF/f3of/
-sandbox/
+sandbox/
+Testing/Temporary/CTestCostData.txt
+Testing/Temporary/LastTest.log