Stop catching non error throwables such as SystemExit

        * Convert "except:" to "except Exception:"
        * Use log.exception instead of directly calling traceback
        * Remove unused imports
        * Fix a typos
        * Replace tabs with spaces for combatibility issues
diff --git a/TestON/core/xmldict.py b/TestON/core/xmldict.py
index 34e9cfc..f873014 100644
--- a/TestON/core/xmldict.py
+++ b/TestON/core/xmldict.py
@@ -37,7 +37,7 @@
         root = ElementTree.XML(root_or_str)
     try :
         return {root.tag: _from_xml(root, strict)}
-    except :
+    except Exception:
         return None
 
 def dict_to_xml(dict_xml):