Merge pull request #9 from pv/topical-software

Update topical software page to match wiki
Add new theme as a submodule
Use the new Bootstrap-based theme
Update .gitignore
Fix navigation hierarchy
Update scipy-sphinx-theme
Link scipylib and scipystack to navigation
Remove duplicate readme
Fix top level link name to scipy.org
Add link to scipy central
Fix text align + padding on front page
Include install to nav tree
Split the content to 'scipy community' and 'scipy (and numpy) the libraries'
Remove mentions of Trac and outdated code contribution instructions
Move steering committee to bottom --- more important things first
Update scipy-sphinx-theme submodule location
Hide Sphinx-style next/prev navigation links
Mark external links in the navigation bar