Add global navigation to documentation

Changed document template in documentation to add a global nav
bar that includes links to the OpenShift Origin home page
and the docs home page
Add origin asciidoc theme to documentation

Including compiled and source files
Add resources for origin asciidoc theme to documentation
Change default documentation body font to match OpenShift font list
Fix small issues with documentation theme

* Changed position of logo to make it seem more centered, and added
larger logo for better scaling.
* Added font source stylesheets so that theme files are complete
* Changed header link text to improve readability
Remove unused font files from documentation theme

The theme is referencing the font files used by the site so that
they are more likely to be cached, so the local font files are no
longer needed.
Change documentation build to use origin theme
Merge pull request #3201 from EmilyDirsh/master

Add custom asciidoc theme for the origin documentation