See issue #128.
With the "Save to one single file" setting **disabled** (accessible
via "Edit -> Settings" under the General tab), then using
"File -> Save as..." creates only a portion of the previous project
files and content.
Steps to Reproduce:
1. Open or create project with data (characters, plots, outline, etc.)
2. Ensure existing project is saved with "File -> Save".
3. Choose "File -> Save as..."
4. Enter a new filename and click Save button.
5. Choose "File -> Close Project"
6. Choose "File -> Open" and choose the newly created project filename.
Note that most of the project contents are missing or empty
(plots, outline, etc.).
This enhancement disables smart caching for the first save of the new
project filename so that all project files are saved under the new
filename.
Previously creating a new project with an existing filename would
blindly overwrite the existing project file(s). This could result in
an author accidentally losing all of their work, assuming they did not
have a backup.
This enhancement pops up a warning asking the user if they wish to
overwrite the existing project filename.
