2.7.0

• API cleanup: all version_compare* methods are now replaced with
  version_compare2(), version_compare3(), and version_compare4()
  which are consistent and suggest the number of arguments.
  version_compare_simple(), version_compare_flags(), and
  version_compare_flags2() are thus deprecated and will be removed in
  further releases.
• Also deprecate version_signature_simple() which had no practical use.