[yt-dev] Issue #891: Allow load_amr_grids to take custom refinement factor (yt_analysis/yt)

New issue 891: Allow load_amr_grids to take custom refinement factor https://bitbucket.org/yt_analysis/yt/issue/891/allow-load_amr_grids-to-take-... astrofrog: At the moment, ``load_amr_grids`` hard-codes a refinement factor of 2. Would it be possible to allow the refinement factor to be a parameter to the ``load_amr_grids`` function?