Recent "security fix" to pay attention to contents of ".gitmodules"
while accepting "git push" was a bit overly strict than necessary,
which has been adjusted.

* jk/fsck-gitmodules-gently:
  fsck: downgrade gitmodulesParse default to "info"
  fsck: split ".gitmodules too large" error from parse failure
  fsck: silence stderr when parsing .gitmodules
  config: add options parameter to git_config_from_mem
  config: add CONFIG_ERROR_SILENT handler
  config: turn die_on_error into caller-facing enum