Switch to a more up to date smart-tab repo

The sroccoserra github repo has a number of patches that are not in the
upstream version.  Hopefully these correct the problems I am seeing with
smart-tab-mode not always working.
Merge branch 'master' of https://github.com/rdparker/emacs-config
Merge branch 'master' of https://github.com/rdparker/emacs-config
Merge branch 'master' of https://github.com/rdparker/emacs-config