[Feature Request] Ability to refill flask when not completely empty

[3ncanis]

Right now you can only fill your flask when it's completely empty which results in me dumping it out completely and refilling it constantly if I know I'm going to be away from a water source for a while. It would be nice to just be able to top it off.

Unrelated suggestion but I don't know how to do pull requests and I think:

"item.waterflasks.leather_flask.filled": "Leather Flask of %s",
"item.waterflasks.iron_flask.filled": "Iron Flask of %s",
"item.waterflasks.red_steel_flask.filled": "Red Steel Flask of %s"

is less awkwardly phrased than the current lang file

[Coach-mdl]

You fork the repository you want to edit, make the changes on your fork and then create a pull request on the main repository and select your fork as the repository you want to merge with. That should do it.