* [BREAK] add possibility to download and use multiply

* [BREAK] add possibility to download and use multiply
  Translation files, configurable with Acquire::Translation
  (Closes: #444222, #448216, #550564)
* Ignore :qualifiers after package name in build dependencies
  for now as long we don't understand them (Closes: #558103)
* apt-pkg/contrib/mmap.{cc,h}:
  - extend it to have a growable flag - unused now but maybe...
* apt-pkg/pkgcache.h:
  - use long instead of short for {Ver,Desc}File size,
    patch from Víctor Manuel Jáquez Leal, thanks! (Closes: #538917)
* apt-pkg/acquire-item.cc:
  - allow also to skip the last patch if target is reached,
    thanks Bernhard R. Link! (Closes: #545699)
* ftparchive/writer.{cc,h}:
  - add APT::FTPArchive::AlwaysStat to disable the too aggressive
    caching if versions are build multiply times (not recommend)
    Patch by Christoph Goehre, thanks! (Closes: #463260)