Merge VectorFileSensor, VectorFileEffector to FileIORegion

[breznak]

As the current names are a bit confusing, and merging the 2 would share quite a lot of common code (both need to check for the file, ...)

Sensor = reader, Effector = writer.

The simplified usage would be

Region rIn = FileIORegion("region1", "read", "path/myFile.txt");
...
Region rOut = FileIORegion("region3, "write", "output.csv");

I'm not sure how much API-breaking would be removing the 2 classes and merging the functionality to 1, but we could provide wrappers to keep the old API.

[dkeeney]

I like the idea of changing the name. FileIORegion is much more understandable.

Combining them would be ok I guess. When compute( ) is called...which operation is performed? A read or a write. I guess it could depend on how the file is opened.

Fairly low priority I would think.

[breznak]

When compute( ) is called...which operation is performed? A read or a write. I guess it could depend on how the file is opened.

In a constructor param, indicating input/output type. In the example "read", "write"

[breznak]

Before, with this issue comes cleanup of VectorFile itself #135