* Bug 16549 fixed: simple script crashed Scilab in GUI mode

* Bug 16549 fixed: simple script crashed Scilab in GUI mode

https://bugzilla.scilab.org/show_bug.cgi?id=16549

This patch fixes the problem and reconsiders the processing
of carriage returns in Scilab output. Only the last occurence was
considered in https://codereview.scilab.org/#/c/21166/

Now the output is exactly the same in GUI and CLI mode:

--> mprintf("%s\n123456\rabc\rZ",getscilabmode())
STD
Zbc456

--> mprintf("%s\n123456\rabc\rZ",getscilabmode())
NW
Zbc456

Moreover, one line counter display is now supported in all modes:

for i=1:10000; mprintf("%05d\r",i);end

Change-Id: I82f05d115afc2911466b52230cd667dee3397db2