Fixing improper / handling

This might be as old as TShock itself. Also, you might as well do &
args.Text != "/" instead of Length, it is just a matter of taste.
Fixing Heart and Star requiring inventory slot

Those don't ever get to inventory, they are consumed by players :)
Coin Gun is not eligible for this ;)
& -> &&
Merge pull request #631 from simon311/general-devel

Fixing a few old "issues"