Excel needs to be visible by default.

The excel files defaulting to invisible makes them almost impossible to work with. They should be visible by default as the user will want to interact with them while using Dynamo. Having them invisible also makes it really difficult to know whether excel is still running or how many instances of excel are running.

This fix simply changes the default to show excel.

PTAL:
- [ ] @aparajit-pratap 

Require Merge:

- [ ] Revit2015