append_repo: use Atom.with_repo()
tests.main(): disable colors when appropriate
repoman: exempt multilib-minimal for get_libdir

This will fix bug #461944.
Task: implement __repr__
autounmask: remove faulty reset_pkg() function

This function did not work as intended, due to the pkg variable being
updated in the wrong scope.
_get_slot_re: relocate due to circular import
repoman: export GNUPGHOME to git, bug #462362
config: make circular vartree import lazy
Task.__repr__: handle python-trace
Use autounmask for subslot conflict, bug #461464.
_iter_similar_available: do built checks together
manifest2MiscfileFilter: remove redundant checks

Checks for directory names are not needed since only regular files
are passed in here.
portageq: fix envvar -v, bug #462412