Indigo 0.12.1

Fixed

• Cache encode fix (BUG 2); session guard macro (BUG 1); PARITY.md updated.
• Indentation/formatting cleaned.
• Build info included in diagnostics.

Added

• Cache codec/store (feat/oncard-cache, v1 format).

Changed

• Indigo version: 0.12.1 (linear from 0.12.0).