Merge branch 'pz/fetch-submodule-errors-config' into seen

Merge branch 'pz/fetch-submodule-errors-config' into seen

The 'git fetch' command has been updated to allow configuring how
submodule fetch errors are handled.  A new configuration variable
'fetch.submoduleErrors' and a corresponding '--submodule-errors'
command-line option have been introduced, allowing users to make
submodule fetch errors non-fatal (warn instead of fail).
Additionally, a premature failure during recursive submodule
fetches has been fixed by deferring the error until the OID-based
retry phase also fails.

* pz/fetch-submodule-errors-config:
  fetch: add fetch.submoduleErrors to make submodule fetch errors non-fatal
  submodule: fix premature failure in recursive submodule fetch