libalgorithm-diff-perl: add 1.15

[from README]
This is a module for computing the difference between two files, two
strings, or any other two lists of things.  It uses an  intelligent
algorithm similar to (or identical to) the one used by the Unix `diff'
program.   It is guaranteed to find the *smallest possible* set of
differences.

* Add ${CPAN_MIRROR} option

Signed-off-by: Tim Orling <TicoTimo@gmail.com>