Clear file name from Save As dialog

[Cuperino]

Is your feature request related to a problem or a limitation? Please describe...
The Save As dialog remembers the last filename that was typed. That is inconvenient when saving a remote document locally, as it may lead to previously saved files being accidentally overwritten.

Describe the solution you'd prefer

• Clear file name from Save As dialog each time the dialog is opened.

Describe alternatives you've considered

• Clear file name from Save As dialog to prevent previous file save from being accidentally overwritten.
• Filter the URL for a name to set automatically for the user

[Cuperino]

Labs files API doesn't allow manually changing file or currentFile properties.