Reset IFS to default in finalize_command

This ensures we don't hit any problems lower down the stack due to IFS
having been set to the empty string when reading lines from the
instruction sheet.

Signed-off-by: John Keeping <john@keeping.me.uk>
Add --autocontinue option

This allows the integration to continue without stopping if the user has
the rerere mechanism enabled and it successfully resolves all conflicts.

Signed-off-by: John Keeping <john@keeping.me.uk>
Merge branch 'autocontinue-feature'

Introduces a way to avoid pausing when a conflicted merge is fully
resolved by Git's rerere mechanism.

* autocontinue-feature:
  Add --autocontinue option
  Reset IFS to default in finalize_command