We can actually differentiate between copies and renames in Hg, so lets

add support for another change type, 'copies'. The previous implementation
for Hg was also slightly flawed in the way that it mixed sources with
targets.

src/IDF/Scm/Git.php

@@ -67,6 +67,7 @@ class IDF_Scm_Git extends IDF_Scm
             'additions'  => array(),
             'deletions'  => array(),
             'renames'    => array(),
+            'copies'     => array(),
             'patches'    => array(),
             'properties' => array(),
         );