Layer export defaults to ilastik executable path

[btbest]

I just tried exporting a raw data layer from Data Selection (dataset location: project internal) to {dataset_dir}/custom_filename.h5 and the export ended up in path/to/ilastik/{dataset_dir}/custom_filename.h5.

For a project internal file, {dataset_dir} should translate to the project file dir. Clearly the layer export isn't interpreting the magic placeholder at all, but even then it should in general default to the user home, not the ilastik executable dir.

Unrelated to this, but sort of note to self: I'm also confused by the behaviour storing the last entered path. I didn't save the project file, but the next time I opened the same layer export dialog, the path was changed to {dataset_dir}/Raw Data.h5 and the format changed to hdf5 (I had selected compressed hdf5). I guess we're tracking the last used path in the preferences; but when I first opened the project file, the dialog showed a linux path from the system the file was created on - so that must've come from the project file...