issue 131 try to use tiff source first

[cooperlab]

When interacting with slide metadata in configure.py, try to use tiff tile source first then fall back to openslide if that fails. The openslide tile source may be leaking.

[Leengit]

Looks good. Also, could do something similar instead of

HistomicsStream/histomics_stream/configure.py

Lines 1064 to 1068 in d29ee69

	ts = (
	large_image_source_tiff.open(filename)
	if os.path.splitext(filename)[1] in (".tif", ".tiff", ".svs")
	else large_image.open(filename)
	)

. Also, we probably don't need to import at both the edited location and

HistomicsStream/histomics_stream/configure.py

Lines 24 to 25 in d29ee69

	import large_image
	import large_image_source_tiff

.

[Leengit]

Good as is, or do more.

[cooperlab]

It's good as-is. Large-image still ends up calling openslide even when using tiff source, but I think we should still keep this.