[patch] TitleFormatString

Hi,

I have picked "TitleFormatString" quest from TODO list and have implemented it. Now the title of the terminal is not hardcoded, but can be modified in the config file by changing TitleFormatString variable.

I am new to this codebase, so I am interested in any comments on this patch. From new-comer's view, I am not sure why terminal title is changed during info_win change event, and not for example in main_win_set_title?

I am not a user of GNU screen, cannot really test it, so I guess this has to be checked out :-)

I hope link is OK:
http://en.file-upload.net/download-12208211/main_window_title.diff.html

Thanks,
K