Fix package name renaming for classes like debian.bbclass:

Fix package name renaming for classes like debian.bbclass:
  package.bbclass now tracks any package renaming performed using PKG_*.
  When a package is built, the runtime variables are translated using
  this cached information which is stored in staging.

  From now on, only use package names are valid in runtime variables like
  RDEPENDS, RRECOMMENDS and RSUGGESTS. eg. fontconfig-dev is correct,
  libfontconfig-dev would be wrong.

  As debian.bbclass can't determine package renaming until after a
  package's contents is known, the class has to set BUILD_ALL_DEPS = "1".

  This also means OE is no longer forced into one package renaming scheme.