the underlying metaphor refers to an inhumane practice, so using it
casually is rightfully offensive to many people. it isn't even a
particularly apt metaphor, as it suggests a strict hierarchy that is
counter to mbsync's highly symmetrical mode of operation.
the far/near terminology has been chosen as the replacement, as it is a
natural fit for the push/pull terminology. on the downside, due to these
not being nouns, a few uses are a bit awkward, and several others had to
be amended to include 'side'. also, it's conceptually quite close to
remote/local, which matches the typical use case, but is maybe a bit too
suggestive of actually non-existing limitations.
the new f/n suffixes of the -C/-R/-X options clash with pre-existing
options, so direct concatenation of short options is even less practical
than before (some suffixes of -D already clashed), but doing that leads
to unreadable command lines anyway.
as with previous deprecations, all pre-existing command line and config
options keep working, but yield a warning. the state files are silently
upgraded.
... by making a lot of objects unsigned, and some signed.
casts which lose precision and change the sign in one go (ssize_t and
time_t to uint on LP64) are made explicit as well.