prepared changelog + incr version to release 2.4.2
documentation update
Fix segfault in import command if uid or gid cannot be resolved.
incr to version 2.4.2-2 (2.4.2+1patch)
More statistics about changelog processing speed.
Added additional information about current migration: nb skipped and nb errors.
MySQL error ER_QUERY_INTERRUPTED is retryable.
Optimization for applying migration policies: a migration pass restarts
from the mtime of the first eligible file in the previous pass.
This avoids always rechecking old whitelisted entries.
This optimization is automatically disabled when the daemon starts,
or if no eligible entry is found, so it finally rechecks the whitelisted entries.
Fixed wrong order for status description in migration policies.
rbh-report: fix bad display of total volume for HSM modes with -u or -g.