v1.7.1

1. Remove the __va_list_tag declaration from the tree when parsing with CastXML

   The __va_list_tag declarations are internal declarations, which are often
   not needed. They are for example polluting the declarations tree when running
   pyplusplus.

   This is optional but on by default. To still load the __va_list_tag declarations
   in the tree, a config flag can be set like this: config.flags = ["f1"],
   or by passing the flags=["f1"] argument the config setup.

2. Some code cleanup

3. Build new package for pypi. The 1.7.0 upload has gone wrong ...