Arguments passed to `run_plugin` replace backslash with forward slash

[matham]

I was using BigStitcher from pyimagej on Windows and needed to pass in paths. But, BigStitcher would choke on the paths claiming it can't find files there.

I traced down the issue to pyimagej automatically replacing backslashes with a forward slash. When I removed this, BigStitcher finally worked.

https://github.com/imagej/pyimagej/blob/17fdca871234d230c8f1b2f70b950beb4a22c779/src/imagej/init.py#L712

Should this replacement be optional, perhaps guarded behind a switch, like ij1_style!? I ended up replicating the format code and passing in args as a string, without this replacement.