Bug#731666: suggest to think about testing before uploading to unstable.

[peter green <plugwash@p10link.net>]

Package: developers-reference

I just had a conversation with pabs on irc about developers apparently 
failing to think about thier packages testing status before uploading to 
unstable and he suggested that something should be in the developers 
reference. I'm not sure where it would fit best though, in the uploading 
section or in the testing sections. Something along the lines of 
(wording could almost certainly be improved, I such at english)

"you should think about the status of your package with relation to 
testing before uploading to unstable. If you have a version in unstable 
waiting to migrate then it is generally a good idea to let it migrate 
before uploading another new version. You should also check the package 
tracking system for transition warnings to avoid making uploads that 
disrupt ongoing transitions."