Cleaner boundaries between libertem-specific code and the rest

[sk1p]

Modules imported from the main libertem package, which will become "de-facto public" interfaces (meaning we will have to coordinate changes to these interfaces with libertem_blobfinder):

• libertem.masks
• libertem.analysis.gridmatching: used for frame visualization and refinement
• libertem.common.container: MaskContainer used in the SparseCorrelationUDF
• libertem.utils for frame_peaks

[sk1p]

Also, which parts of the blobfinder don't need to depend on libertem, which can be made more reusable?

[uellue]

The separation was now done in #14. Yes, managing the net of dependencies will be a bit of work while the restructuring is ongoing. All the packages you mention are candidates to become indedependent of LiberTEM core.

[sk1p]

At least the clean separation of the core correlation code from the libertem-dependent part is done as of #87 + #90

[sk1p]

I consider this done for now, further restructuring is separate