Green manure v2.1

The green manure mod adds all cultivators, plows and Drill in the game added the ability to fertilize by the incorporation of a cover crop.
For those to whom the term green manure nothing says here what to read: http://de.wikipedia.org/wiki/Gründüngung
Effect of the mods: When the ground is incorporating plants that at least one step * before * are ripe (green wheat, flowering rapeseed etc.) thereby fertilized. This also works with rotten harvest - catch crops can be partially freeze off over the winter to then incorporate in the spring.
Why such a mod? Because such methods work in the real agriculture are quite common and so far can not be mapped properly in the LS. And no, of the clout this way of working is of course not against a 40m syringe. Should they also not :)
Also for LS15 my wish to the Mapper: Builds but a few fast-growing cover crops for this purpose one :)


Changelog:
V2.0: Converts to LS15