
Globals in script files. Note that they are available on a per window
basis, so __pl.legend[3] returns the status of the legend of figure 3.

The only exception is __pl.lab_str, which by itself is a string array.
This can cause problems if, when in hold mode, one changes to another
picture and plot something; reverting to the original picture and
issuing more plot commands lost the previous line legend text.

__pl.legend			legend status
__pl.legend_xpos			x position
__pl.legend_ypos

__pl.lab_pos		line label position
__pl.lab_str					string
__pl.lab_col					color

__pl.multi			multiplot status
__pl.multi_row					number of rows
__pl.multic_col							columns

__pl.type			type of plot (log, polar, ...)
__pl.items			number of items to plot
__pl.struct			the x,y data to plot

__pl.axis_st		axis status
__pl.axis				values

__pl.xticks			xtick interval, number of minor xtick
__pl.yticks

__pl.az				azimuth
__pl.alt			altitude

__pl.grid			grid status

__pl.lstyle			increase line style

__pl.plcol			current line color
__pl.pllsty					line style
__pl.line_count				line count (number to appear in legend)
