diffutils: Upgrade to version 3.2

diffutils: Upgrade to version 3.2

The majority of the changes were inherited from gnulib.  There were only
a few observable differences from version 3.0:

Release 3.2 (2011-09-02) [stable]
Release 3.1 (2011-08-10) [stable]

Bug fixes
===================
diff no longer reports spurious differences merely because two entries
in the same directory have names that compare equal in the current
locale, or compare equal because --ignore-file-name-case was given.

Changes in behavior
===================
--ignore-file-name-case now applies at the top level too.
For example, "diff dir inIt" might compare "dir/Init" to "inIt".

New features
===================
diff and sdiff have a new option --ignore-trailing-space (-Z).