added multi-dimensional integration routines based on finite difference
meshers to allow more efficient pricing using Fokker-Planck equations
change Fokker-Planck test case to Heston model with Feller constraint
being violated
change tolerance to relative tolerance (thanks to Johannes)
change tolerance to relative tolerance (thanks to Johannes)
upps.. Boost 1.39 does not support sum_kahan (thanks to Johannes
Goettker Schnetmann)
fixed integration over the principle branch for the complex logarithm
fixed comment
removed misleading function name
towards slv
towards slv
Merge branch 'slv' of https://github.com/jschnetm/quantlib into slv