Provide more configuration options

[rillig-nm]

Pitclipse already provides configuration for several options, but not all that are mentioned on pitest.org. I miss especially the timeoutConst and timeoutFactor options, but the others also shouldn’t be too hard to implement. See http://pitest.org/quickstart/commandline/ for the full list.

[philglover]

Adding those two options shouldn't be too difficult. The challenge with adding new options is in terms of UI. I will post something on the pitusers forum about this in a week or so when I've had chance to gather my thoughts.

[velo]

Would be nice to have targetClasses option as well