feat: 0.2.6 Port amboso 2.0.3 additions

[jgabaut]

Added

• New -O flag to pass stego_dir path
  • Closes #99
• New constants to lock in patch-specific behaviour of amboso >2.0
• Interpreter branch for stego.lock in do_query()
• Print compatibility level with -v -V(>3)
• Try parsing legacy format stego.lock when running as <2.0
• Experimental Makefile parsing, with -Xx
  • Handle -d, -L, -q when in Makefile parser mode for output control
  • Closes #98

Changed

• Expect stego.lock at stego_dir, not amboso_dir
  • New default is "."
  • For now, there's a safety check to still look at the old path when failing to find stego at first
  • Our stego.lock was moved to repo root
• Try reading anvil_kern from stego.lock