This is mostly mechanical and changes how loggers are instantiated.
Logger is now associated with a context, passed around all methods,
(most methods had ctx, but had to add it in a few missing places).
By default Kopia does not produce any logs, but it can be overridden,
either locally for a nested context, by calling
ctx = logging.WithLogger(ctx, newLoggerFunc)
To override logs globally, call logging.SetDefaultLogger(newLoggerFunc)
This refactoring allowed removing dependency from Kopia repo
and go-logging library (the CLI still uses it, though).
It is now also possible to have all test methods emit logs using
t.Logf() so that they show up in failure reports, which should make
debugging of test failures suck less.
The splitter in question was depending on
github.com/silvasur/buzhash which is not licensed according to FOSSA bot
Switched to new faster implementation of buzhash, which is
unfortunately incompatible and will split the objects in different
places.
This change is be semi-breaking - old repositories can be read, but
when uploading large objects they will be re-uploaded where previously
they would be de-duped.
Also added 'benchmark splitters' subcommand and moved 'block cryptobenchmark'
subcommand to 'benchmark crypto'.
