pptInsertTextbox: Insert textbox on current slide.
In andrie/braidppt: An extension of braid to deal with PowerPoint output

Insert textbox on current slide.

  pptInsertTextbox(ppt, text,
    position = c(100, 100, 150, 50),
    fontControl = list(Color = 1, Bold = FALSE, Italic = FALSE, Underline = FALSE),
    paraControl = list(Alignment = 2))

`position`	Numeric vector of length 4 indicating c(top, left, width, height)
`fontControl`	List of Properties and values that controls the font. Passed to `ppt.Current.Slide.Shapes.Item(n).TextFrame.Tex`
`paraControl`	List of Properties and values that controls ParagraphFormat. The alignment property takes integer values (e.g. 1=left, 2=centre, 3=right).
`ppt`	Pointer to ppt object, generated by `pptNew`
`text`	Slide text