Issue #24 - Sort authors by lastname || firstname

If several authors have the same lastname, they are swapped in the list between the different runs.

lib/Koha/Release.pm

@@ -276,6 +276,19 @@ qx|git log --pretty=format:'~-%ct,%an,%ae%n%s%n%n%b%n~----~' $range 2>/dev/null|
             }
         }
 
+        sub sort_authors {
+            my $authors = shift;
+            sort {
+              my ($alast) = $a =~ /(\S+)$/;
+              my ($blast) = $b =~ /(\S+)$/;
+              my $cmp = lc($alast) cmp lc($blast);
+              return $cmp if $cmp;
+
+              my ($a2last) = $a =~ /(\S+)\s\S+$/;
+              my ($b2last) = $b =~ /(\S+)\s\S+$/;
+              lc($a2last) cmp lc($b2last);
+            } keys %$authors
+        }
         if (@commits) {
             say "Range $range: ", scalar(@commits), " commits";
             $self->range_commits( \@commits );
@@ -284,11 +297,7 @@ qx|git log --pretty=format:'~-%ct,%an,%ae%n%s%n%n%b%n~----~' $range 2>/dev/null|
             $self->range_authors(
                 [
                     map { { name => $_, commits => $authors->{$_} } }
-                      sort {
-                        my ($alast) = $a =~ /(\S+)$/;
-                        my ($blast) = $b =~ /(\S+)$/;
-                        lc($alast) cmp lc($blast)
-                      } keys %{$authors}
+                      sort_authors $authors
                 ]
             );
 
@@ -296,23 +305,15 @@ qx|git log --pretty=format:'~-%ct,%an,%ae%n%s%n%n%b%n~----~' $range 2>/dev/null|
             $self->range_signers(
                 [
                     map { { name => $_, signoffs => $signers->{$_} } }
-                      sort {
-                        my ($alast) = $a =~ /(\S+)$/;
-                        my ($blast) = $b =~ /(\S+)$/;
-                        lc($alast) cmp lc($blast)
-                      } keys %{$signers}
+                      sort_authors $signers
                 ]
             );
-            
+
             # alphabetised by last 'name' list of mentors
             $self->range_mentors(
                 [
                     map { { name => $_, mentees => $mentors->{$_} } }
-                      sort {
-                        my ($alast) = $a =~ /(\S+)$/;
-                        my ($blast) = $b =~ /(\S+)$/;
-                        lc($alast) cmp lc($blast)
-                      } keys %{$mentors}
+                      sort_authors $mentors
                 ]
             );