Use 12byte revision hashes in reports for consistency with developer.mbed.org

.lib references use full 40byte hashes

Author: screamerbg

mbed/mbed.py

@@ -871,7 +871,7 @@ def revtype(cls, rev, ret_rev=False):
         if rev is None or len(rev) == 0:
             return 'latest' + (' revision in the current branch' if ret_rev else '')
         elif re.match(r'^([a-zA-Z0-9]{12,40})$', rev) or re.match(r'^([0-9]+)$', rev):
-            return 'rev' + (' #'+rev if ret_rev else '')
+            return 'rev' + (' #'+rev[0:12] if ret_rev else '')
         else:
             return 'branch' + (' '+rev if ret_rev else '')