0.95-pre1 bug with Arc connectors.

["Rob McDonald" <robm asdl gatech edu>]

> the Dia for Windows 0.95-pre1 installer is available from
> http://dia-installer.sourceforge.net


I'm not sure if this is a Windows problem, or a problem general to
0.95-pre1.

On 0.95-pre1 Windows, arc connections sometimes vanish.  This behaves
somewhat like a problem with a trig function.  Maybe a classic atan vs.
atan2 issue.  Basically, when you grab the control point and try to adjust
how curved an arc is, for some ranges of arc, the line disappears.  This can
be worked around by switching the starting and ending points.  Then, the
point of dissappearance is reversed...

I do not see this behavior on 0.94 Linux.

              Rob