When `pptx.userProperLayoutMaster` called, XML of a master file and layout files can be passed to the presentation. Otherwise, works as originally.
When `pptx.userProperLayoutMaster` called, XML of a master file and layout files can be passed to the presentation. Otherwise, works as originally.

gitbrent/PptxGenJS,gitbrent/PptxGenJS,gitbrent/PptxGenJS