Classes in parser.py are already split to stack.py and
template.py, it's not recommended to import it.
Closes-Bug: #1442011
Change-Id: Ia8cc0ca07e7926fe8b7d9f5c89b39053a799e689
The initial bug was for HOT, but this fixes the same issue
in CFN too.
1) all calls to template[section] should return {} and not
None by default (hot was correct, but not cfn)
2) the validate needs to access the raw template "self.t" so
make sure we have a similar logic there too.
3) when warning for zero resources, look for len(resoruces) == 0 not
None.
Change-Id: Iee6e2abbf13173c17d92f47b8a7efe207c29a984
Closes-bug: #1339893