Have some warning mechanism during updates that change default behaviour

[rousisk]

Hello,

First of all thank you all for your great work!

I recently updated janus and I noticed some drastic changes on the way syntastic works. It no longer checked my files and after some searching and setting ruby files to active mode, the checking behaviour was completely different from what I was used to:

1. The checking happens automatically on opening a file, which makes it really slow for legacy code with a lot of issues
2. The quickfix list opens by default which makes working with vertical/horizontal splits difficult (for me).

I was sure that I screwed something in my configuration so it took me quite some time to find #679 and eventually configure syntastic to what I was used to.

This is not meant as a rant - I understand that janus is a collection of plugins and it's wise to stick with their defaults whenever possible.

I am just wondering whether we can have a warning mechanism for such kind of changes during janus update. Just an idea!

Thanks again for all your hard work.