nanogui: Thread: Workarea patch

Hi,

The attached workarea.patch adds support for the workarea feature.
This is useful, if you want to write Taskbars etc. that shouldn't be
overlapped by a maximized window.

Additionally I found a bug in winres.c: The file pointer to the resource
file wasn't closed on exit and
the mwFindResource function may end in an endless loop on releasing the last
ressource if
you don't do error checking on fseek, so I added error checking.
The winres.patch supersedes my patch from last Friday.

Regards,

DI (FH) Ludwig Ertl
Software Engineering
Computer Software Production GmbH
Fockygasse 4
1120 Wien
E-Mail: ####@####.####
Web: http://www.csp.at