Add a docs button to the main plugin prefs window
add a help button to each plug-in's pref pane
Create a new info pane and tie it to the current plugin's help
Use sensible base URLs for HTML views and tie up QSStyles.css to plugin help

Instead of using resource:file.css (scheme:file syntax) just use sensible base URLs then make all other files load from this relative.
shift the box back into the center of mainView
Merge pull request #1364 from quicksilver/pluginHelp2

Plugin help. Fixes #999