TeXWorks should have an option to always prompt the user before updating to a file changed underneath it

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Open a saved file in TeXworks
2. Open the same file in another program
3. Edit the file in the other program and save it.

What is the expected output? What do you see instead?
I would like to be able to select an option in preferences that makes it so 
that, regardless of whether or not I've edited the file since the last change, 
TeXworks will prompt me on whether or not to reload the changed file.

What version of the product are you using? On what operating system?
Windows 7, TeXworks 0.4.3 r.857 (MiKTeX 2.9)

Please provide any additional information below.
This would be especially useful for editing documents inside dropbox when I 
also have dropbox running on another computer with a broken filesystem like 
AFS; dropbox sometimes fails at determining which is the newer file, and 
replaces my existing file with a blank one.  I don't want this to interrupt my 
coding.

Original issue reported on code.google.com by [email protected] on 27 Apr 2012 at 4:37