Drill steel cost setting.

- Bugfix: missing drillable settings headers.
- Automatically removes drillables that no longer exists.
- Bugfix in Utils.cs.
- New Utils method: DefExistsByDefName().
- About.xml.
- Assembly info.
- Refactor.

Bugfix: drillables height calculation

Update for version 1.3.

Updated to v1.2 and added Dutch and Japanese translations.

Note that you must clear your mod settings when upgrading from v1.1 --> v1.2.

[Auto-generated text]: Update on 3/9/2020 10:22:53 AM.

Can now drill all items in the game.

Fixed a bug for mod settings that set ores to undrillable.

Fixed mod settings not being applied.

Initial upload.