libopenblas-dev is not being removed cleanly

[Pavan Yalamanchili]

Steps to reproduce:

1) apt-get install libopenblas-dev libopenblas-base
This installs openblas and updates the alternatives for libblas and liblapack

2) apt-get remove libopenblas-dev libopenblas-base

This removes openblas and reverts the alternative for libblas. But liblapack still points to the non existent openblas-base/liblapack.so

System information:

 $ lsb_release -rd
Description: Ubuntu 14.10
Release: 14.10

$ apt-cache policy libopenblas-base libopenblas-dev
libopenblas-base:
  Installed: (none)
  Candidate: 0.2.10-1
  Version table:
     0.2.10-1 0
        500 http://archive.ubuntu.com/ubuntu/ utopic/universe amd64 Packages
libopenblas-dev:
  Installed: (none)
  Candidate: 0.2.10-1
  Version table:
     0.2.10-1 0
        500 http://archive.ubuntu.com/ubuntu/ utopic/universe amd64 Packages