[PATCH 0/4] Make the documentation consistent for --track and --notrack

Hi,

Here is the patchset I sent before, hopefully in a format more palatable
to the list.

The first three patches try to improve the documentation for git-branch
and git-checkout, adding docs for --track and --notrack to
git-branch.txt, and improving the ones that were in git-checkout.txt.

The last patch is for git-pull.sh; it gives the user a hint of what to
do when there's no branch configured to merge from.

  Federico