Add abbreviations to the post editor

[Clorith]

Quite surprised this isn't a thing already, but with todays large amount of short hands and abbreviations, I believe it would be beneficial to the users to have easy access to the <abbr> tag via the visual editor.

[azaozz]

Agreed, however considering how many users would know what is it for and eventually use it, not sure its warranted to add another button to the toolbar. There are several other buttons that would be beneficial: <code>, <q>, <ins>, <time>, perhaps <samp> and <cite>... Maybe we can make another custom TinyMCE plugin and add all of these in a drop-down?