Function: plotstring
Section: graphic
C-Name: plotstring
Prototype: vLsD0,L,
Help: plotstring(w,x,{flags=0}): draw in rectwindow w the string
 corresponding to x. Bits 1 and 2 of flag regulate horizontal alignment: left
 if 0, right if 2, center if 1. Bits 4 and 8 regulate vertical alignment:
 bottom if 0, top if 8, v-center if 4. Can insert additional gap between
 point and string: horizontal if bit 16 is set, vertical if bit 32 is set.
Doc: draw on the rectwindow $w$ the String $x$ (see \secref{se:strings}), at
 the current position of the cursor.

 $\fl$ is used for justification: bits 1 and 2 regulate horizontal alignment:
 left if 0, right if 2, center if 1. Bits 4 and 8 regulate vertical
 alignment: bottom if 0, top if 8, v-center if 4. Can insert additional small
 gap between point and string: horizontal if bit 16 is set, vertical if bit
 32 is set (see the tutorial for an example).
