Fix some minor whitespace inconsistencies
Remove the redundant PSR-0 headline
Add an index page at `/psr`
Restructure the PSR folders using "alias" to create the redirect pages
Adjust the links in the index document to the new URLs
Add the PSR-0 translations as well as the necessary includes and CSS code
Add the PSR-1 translations
Add the PSR-2 translations
Add the PSR-3 translations
Adjust the sidebar links
Manually create the redirect pages since the Jekyll "alias" plugin is not available
Merge pull request #85 from leofeyer/master

Website changes as discussed