add new background image of sf
change the implementation of the splash image so that we can display images that do not look good/well at their center.
slight refactoring + performance improvement of the navbar show/hide code
Merge pull request #44 from rexk/feature/allow-for-more-images

add new background image of sf
Merge branch 'master' of https://github.com/rexk/skyportsystems.github.io