Make ElementalObject more useful

[Lafolie]

ElementalObject needs a bit of a refactor:

• addBaseElement should maybe be renamed
• add/remove element shoud add 2 instead of 1
• add/remove elements should have the following options:
  • add/remove only the provided element
  • add/remove provided element, and auto add/remove weakness (e.g. fire+2, water-2)
  • add/remove provided element, and auto add/remove weakness and sub-resist (e.g. fire+2, water-2, ice+2)
  • possible same as previous, but sub-resist is +1 (e.g. firre+2, water-2, ice+1)
• function to get the most prevalent attribute for an element (whether to absorb/ignore/resist damage etc)

[Lafolie]

This has been done.