Reduce costs of printing press

Backport of https://github.com/igotyou/FactoryMod/pull/9 against currently live copy.

Following http://www.reddit.com/r/Civcraft/comments/1xj9yh/suggestion_lower_the_cost_of_printing_books_in/ have put in a config to reduce the costs of the printing press. This was also my observation - that people weren't using it in practice due to the cost of printing.