added b=0 case to Levy engine for Asian options
improved case runningAvg >> forward for FDM Asian engine
fixed formatting
Merge pull request #61.
Fix delta and Gamma in Ju quadratic engine.

Thanks to Fabien Le Floc'h for the fix.
Increased time steps in convertible-bond test.
Replace explicit allocation with make_shared.
Try to avoid intermittent test failure.

Instead of increasing the tolerance, I tried increasing the number of
grid point in the tree to get a more accurate result.
Merge remote-tracking branch: upstream/master