#20 Check return codes everywhere

[Markus Elfring]

Some checks for return codes are missing.

Examples:
Would you like to add more error handling for return values from "strdup" like in the function "reload_cb" and from "fprintf" in the member function "OutputWindow::print_cb"?
http://xdiskusage.cvs.sourceforge.net/viewvc/xdiskusage/xdiskusage/xdiskusage.C?revision=1.23&view=markup

[Bill Spitzak]

I have generally found that if it runs out of memory it will crash long before any strdup return code can be tested for.