Changelog for `hpc` package

0.6.0.3 May 2016

Bundled with GHC 8.0.1
Improved error messages (#10529)

0.6.0.2 Mar 2015

Bundled with GHC 7.10.1
Allow same Mix file in different dirs (#9619)

0.6.0.1 Mar 2014

Bundled with GHC 7.8.1
Update to Cabal 1.10 format
Drop support for GHC prior to version 7.2.2
Minor improvements to Haddock docs