Added placeholder monsters.

Just more slimes, for now.
Added quality value and stat tweaks.

Code to actually use the new quality value comes next.
Merge branch 'master' of https://github.com/benstreb/RPGme
Some more edits to the json files.

Added a missed comma and a forgotten quality value. Also
some slight wording tweaks.
Added getQuality() to Item.

Plus a couple of really minor logging tweaks.
Merge branch 'master' of https://github.com/benstreb/RPGme