ebuild-ipc: add FifoWriter class
runtests.sh summary: add minimum column width
SchedulerInterface: use loop for proxied attrs
Add QA_AM_MAINTAINER_MODE for bug #450278.
.gitignore: __pycache__/
Add async FileDigester class.
BinpkgVerifier: use async FileDigester
Handle os.write() return code with loop.
MetadataRegen: fix signal interrupt handling

We have to force it out of the scheduling loop before
_termination_check can have an effect.
MetadataRegen: portdbapi.cp_all() already sorted
ManifestScheduler: fix signal interrupt handling
_keep_scheduling: check _terminated.is_set()

This ensures that scheduling loops terminate as soon as possible after
an interrupt is received.
portdbapi.cp_all(): add reverse sort parameter
MetadataRegen: call cp_all for each category

List categories individually, in order to start yielding quicker,
and in order to reduce latency in case of a signal interrupt.
MetadataRegen: simplify _iter_every_cp
If 2 make.conf files found, then warn.

This may give a clue to those who unintentionally end up with 2
make.conf files somehow.
PipeLogger: handle file object for input_fd
parseManifest2: handle space in name, bug 450736
Declare regex literal as such.
ManifestTask: use PipeLogger for monitoring