New setting: preferred protocol, fixes and a new method in PAPI

New setting: preferred protocol. Allows to browse NERDZ using an unique protocol (don't like HTTPS? Then use only HTTP. And viceversa)
New PreferencesAPI method: setValue. Usage discouraged. Read the documentation.
Fixed a big typo in the documentation: getValue was named getSetting!
Merge normalize.css in our default.css. This fixes problems with Chrome and improves the UX with Firefox.
Fixed the post trimmer for Chrome.
TODO: fix the searchbar for Chrome.