PLOT_CI plots confidence intervals and patch between two confidence
interval lines. X is nx1 vector corresponding to a horizontal axis.
Y can be either nx1, nx2, or nx3 matrix.
If Y is nx1 vector, PLOT_CI plots just the main line. If Y is nx2, the
function assumes only two confidence intervals are to plot with the patch
enclosed between them. If Y is matrix of nx3, PLOT_CI plots, the main line,
two confidence interval lines, and also the patch between them.
The main line is specified by 1st column of matrix Y, whereas confidence
intervals are determined by 2nd and 3rd columns.

PLOT_CI(...,parameter1,value1,parameter2,value2,...) allows setting
parameters for the main line, the patch, and the confidence interval lines,
such as line style, line width, color etc.
The function recognizes following parameters:
'MainLineWidth'
'MainLineStyle'
'MainLineColor'
'LineWidth'
'LineStyle'
'LineColor'
'PatchColor'
'PatchAlpha'
'AxesHandle'
'XScale'
'YScale'

All parameters should be self-explanatory, however, all the 'MainLine*'
parameters set the main (middle) line of the graph. All 'Line*'
parameters have the effect on confidence interval lines. If the parameter
'AxesHandle' is provided, PLOT_CI plots on axes specified by AxesHandle.
'XScale' and 'YScale' can change scale of an X or Y axis from 'linear' to
'log'. However, bear in mind that at the moment changing scale to log cases
resets 'PatchAlpha' to 1. It could not be solve at the moment.

H = PLOT_CI(...)
Returns structure of handles of the main line, confidence interval lines
and the patch.