Bug#791173: libstxxl: library transition may be needed when GCC 5 is the default

[D Haley]

Hi All,

Apologies for being late to fix this bug. I had previously looked into 
it and from the above instructions, I had seen the bump was needed, but 
have only just had the time to work on this.

I have contacted upstream to see which of the two options they would 
prefer. My preference is for a soname bump, but this risks being out of 
sync with upstream. I don’t think that is a major problem, as we can fix 
that on a future stxxl release, but if someone is willing to correct me 
here, let me know.

Hopefully I will get a response, and should be able to tackle this next 
weekend.

Thanks.