Space in editor command on windows is not handled gracefully

This bug is similar to #515514.

I tried to use c:\documents and settings\rasmus t. olesen\bin\e.bat as my editor using the "User Configuration" dialog, but bzr-explorer reported lines of the following nature to the console without opening the editor:

QFileSystemWatcher: failed to add paths: C:/Documents and Settings/Rasmus T. Olesen/Application Data/bazaar/2.0/bazaar.conf
QFileSystemWatcher: failed to add paths: tools/main.py

If i surround the editor command with quotes (") it works perfectly, maybe we should just out quotes around the command if it contains spaces automatically, no harm done as far as i can see.

Btw, the e.bat is a windows batch/command script to open the file in emacs. I have it in my path so e.bat also suffices, however just telling it that my editor is called e does not work, maybe that should be reported as a bug too since on windows it is usually up to the operating system to add the .exe, .bat or .cmd extension at the end of program names. Could there be another bug?