Merged from trunk 5350:5366

Merged from trunk 5350:5366

I hate docstrings (WarnerBro)

Remove two old functions, appear to be relics from 2.0.X branch, no longer used
by portage or gentoolkit or esearch (WarnerBro)

When an unprivileged user runs portage (not in the portage group), use
metadata_overlay together with a volatile in-memory cache module in order to
implement cache writes.  This allows, for example, a user who's not in the
portage group to run `ebuild foo.ebuild digest` (issue reported by Charlie
Shepherd <masterdriverz@gentoo.org>).

Add volatile cache module missing from the previous commit.

Pass a cache instance into metadata_overlay since it doesn't have enough
information to construct one itself.

Make metadata_overlay use the autocommits attribute of the underlying database.

Fix inverted EAPI default logic.

Combine two default EAPI settings in portdbapi.aux_get().

Only write repo.stats and repo.fails when the repoman user has write access to
/var/cache/edb.

Show the "Calculating dependencies .. done!" message with --resume since the
spinner now runs inside the depgraph constructor.  Thanks to antarus for
reporting.

startime is set up in treewalk, so no need to do it globally... (WarnerBro)

List package in summary logfile (genone)

disable display of elapsed time for collision-protect as it's for benchmarking
purposes and useless to most people. (genone)

More Docstrings in portage.py (WarnerBro)

move actionmap_deps out of global scope and into doebuild where it is actually
used, add docstrings to config class in the meantime. (WarnerBro)

svn path=/main/branches/prefix/; revision=5374