Pick-up any SpecIF data-set for import into Confluence

[odungern]

So far, only a single demo-project can be imported. The user shall have the opportunity to pick-up a SpecIF data-set

• from the local file system
• from an URL
• from a SpecIF server API (see SpecIF OpenAPI) .... later on, as there is no existing implementation, yet.

No support for versions < v1.0 needed

[odungern]

Explanation: We need a dialog offering to choose a *.specif or .specifz=.specif.zip file from the local disk or to input an URL from where to load such a file. Perhaps it is already there - I don't remember. The priority is for import from local file system.