Item amount placeholder

[aBooDyy]

• Added a new placeholder to return the item amount in the player's inventory (fixes Items #5 ) %checkitem_amount_<Modifiers>%.
• Removed 2 missed debugging messages.
• Made few improvements to the code.

Was planning to move ItemWrapper inner class to its own class, but remembered that you prefer it like this.
Let me know if you want a compiled version to test, my website isn't working atm :(