Reorder buildings based on selected buy-mode

[DanielNoord]

Originally posted by @haninouya in #320 (comment)

While I can make a quick fix to do this, the better solution would be a significant re-write of the code.
Currently CM.Cache has Objects, Objects10 and Objects100 children. It would be better to rewrite Objects into Objects1 as there are multiple occasions in which being able to us the amount would be beneficial.
For example, in this issue by reading Game.buyBulk to decide on which PP-value to sort.
However, as CM.Cache.Objects gets referenced quite often we should take time and care for changing this.