1.2 Update

Nothing too major, but while I work on the next big pack (600 textures so far!) I've got another small update for the Delven set with about 30 additions. New textures include metal-rimmed barrel tops, lantern kitbash sheets, metal grates, windows, quake key markers and wooden steps. Thanks to FifthElephant for the suggestions. I've also fixed a number of stray and miscoloured pixels across various textures.