Enable possibility to check spelling in new (unsaved) documents

[GegznaV]

Now wellspell.addin requires the documents to be saved on a hard drive before using the tool:

"Unknown source file path. Is the file where you apply 'wellspell' saved?"

And this creates inconvenience in some situations.

Would it be possible to use the wellspell.addin in new (unsaved) documents? Should any part of functionality be lost in order to have the feature?