Merged from trunk 6590:6592

   Merged from trunk 6590:6592

   +------------------------------------------------------------------------+
   | 6590    | Save memory by not holding a reference to the PackageIndex   |
   | zmedico | when it's not being used.                                    |
   |---------+--------------------------------------------------------------|
   | 6591    | Pass a temporary file name to the package phase in the       |
   | zmedico | environment variable PORTAGE_BINPKG_TMPFILE and move the     |
   |         | temporary file into place inside binarytree.inject(). This   |
   |         | allows binarytree.inject() to perform the move while holding |
   |         | a lock.                                                      |
   |---------+--------------------------------------------------------------|
   | 6592    | Add a 'ignore-previously-merged' config option which gives   |
   | zmedico | similar behavior to the --noconfmem emerge option.           |
   +------------------------------------------------------------------------+

svn path=/main/branches/prefix/; revision=6598