Provide a way to set an absolute dialog position, regardless of window size

This happens on Chrome/Windows, although the issue seems to be generic.

See also on Stack Overflow: http://stackoverflow.com/q/8485867/11236

Currently, if a dialog is given absolute position, it will not obey this position if the window is not large enough.

http://jsbin.com/ifetag

Here is a fix suggested on Stack Overflow: http://stackoverflow.com/a/8486190/11236 (http://stackoverflow.com/a/8486190/11236)