Allow specifications to overwrite grow/harvest/build times

[pzich]

I found that recipe times can be changed by setting CycleDurationInHours for a given recipe, but as far as I can tell, there is no way to change how long it takes a tree or crop to grow, how long it takes to cut down a tree or harvest a crop, or how long it takes for a building to be built. It would be great if these could also be adjusted without needing to write code or use Unity.