Implement "fast-pass" option to parse and generate output

[BeyerMart]

Currently, the minimum amount of clicks to get output is two.

With this feature, if all necessary info is set up (e.g. output path), parsing and generating output should be done with one single drag and drop.

The "fast-pass" option should only be executed after dragging and dropping.

[BeyerMart]

This Issue is blocked by issue #8 (automatic invoice generation)