Fix stack-show on a TemplateResource with outputs

TemplateResource currently tries to re-download the template.
this is not good, esp. if you have a relative path to a local file.
First see if we have a new template, if not look in the db.

Closes-bug: #1252980
Change-Id: If819aab9ed1360744f8e73f0b6409641e2d8114f
Clean up useless ex variable

When handle exception, if the exception was not used, then there is
no need to use "except Exception as ex", just using "except ValueError"
is good enough.

Change-Id: I495e239cbca20246cb88da166a80bbd4eda1a094
Merge "Clean up useless ex variable"
Merge "Fix stack-show on a TemplateResource with outputs"