[Dart] Dashboard rollover times.

[Brad King]

> Should the "-" in the buildstamp name before the time only be in the 
> directory structure or actual encoded buildstamp used throughout the 
> system.  Not sure how this affects the server XSL scripts.
> 
> What will happen if a client does not update?  Will the build just
> not get reported by the server or will the server crash?
> 
> It looks like the bottom line is that buildstamps are 
> YYYYMMDDHHMM-[Nightly|Experimental|Continous]
> 
> So one change is that Experimentals are now labeled with "-Experimental"
> and nightlies have the hour and minute encoded.
> 
> In general, I do not like forcing clients to update Dart.  However,
> I don't want the code to be too complicated to support both the old
> encoding and new encoding schemes.

I just put in a small change on the branch that will allow the server to
accept Nightly and Experimental builds from clients that have not updated
Dart.  I also changed it to add the hyphen between the date and time.  It
seems to work just fine.

If you could take a look to check that the XSL scripts are okay, then it
shouldn't be a problem to merge these changes into the main tree.

-Brad