Find ways to display help information (icon with tooltips etc)

[rayrfan]

Many features would benefit from a little bit of help info so that users could quickly know a tip on how to use it or how to use it better. There are two mechanisms that could help

1. display an info icon with tooltip, when hovering over it display some text

The Tag selector in the Composer could use such an icon next to it when hovering over to let the user know that she could type in a new tag and hit tab.

2. a dialog which is a modal popup to show help text

The editor could benefit from such a dialog to show users keyboard shortcuts to input certain texts to the editor.