* methods/gpgv.cc:

* methods/gpgv.cc:
  - remove cruft code that caused timestamp/I-M-S issues
* ftparchive/contents.cc:
  - fix error output
* methods/mirror.{cc,h}:
  - only update mirror list on IndexFile updates
* ftparchive/contents.cc:
  - support lzma data members
* ftparchive/multicompress.cc:
  - support lzma output