KTX tools module #14

An equivalent to gdx-tools that could automate some KTX-related operations. Potential candidates:

• Conversion of .properties files to type-safe i18n enums from ktx-i18n.
• Conversion of skin .json definition to type-safe builders from ktx-style.
• Generating type-safe ktx-style builders from an existing Skin instance.
• Extraction of texture region names from .atlas files, which could be saved as a type-safe enum. Useful for both ktx-style builders and general TextureAtlas usage.

Could be implemented as standalone library or Gradle plugin. Or both. The first approach seems the most flexible.

@kotcrab