clonevol: Clonal ordering and visualization

Draw a polygon representing a clone, annotated with cluster label and cellular fraction

1	draw.clone(x, y, wid=1, len=1, col='gray', label=NA, cell.frac=NA)

`x:`	x coordinate
`y:`	y coordinate
`shape:`	c("polygon", "triangle", "parabol")
`wid:`	width of the polygon (representing cellular fraction)
`len:`	length of the polygon
`col:`	fill color of the polygon
`label:`	name of the clone
`cell.frac:`	cellular fraction of the clone
`cell.frac.position:`	position for cell.frac = c('top.left', 'top.right', 'top.mid', 'right.mid', 'right.top', 'right.bottom', 'side', 'top.out')
`cell.frac.top.out.space:`	spacing between cell frac annotation when annotating on top of the plot
`cell.frac.side.arrow.width:`	width of the line and arrow pointing to the top edge of the polygon from the cell frac annotation on top
`variant.names:`	list of variants to highlight inside the polygon
`border.color:`	color of the border
`bell.curve.step:`	vertical distance between the end point of clone bell curve, and its mid point (increase this will make the curve steeper, set this equal to zero will give no curve; use case: sometimes bell of subclone cannot fit parent clone bell, so decrease this will help fitting
`wscale:`	scale the x length of the curve part of the bell plot by this to make sure in a wider pdf output file, the curve part won't be lengthen (wscale should be the ratio of the default width (currently hard-coded as 7) and the pdf page width