Formatting is not removed on CRTL+A DELETE

[Jakub Ś]

This ticked is based on part of #8410 ticket reported by @mrfr0g.

Another issue I have noticed during my tests, is when you execute a ctrl+a or apple+a to >select all the text, and press delete, the bold button remains highlighted. The style does >not exist on the document, so the bold button should be unhighlighted.

1. Clear editor contents
2. Type "test"
3. Press cmd+a on Mac or crtl+a on Win
4. Click bold or italic or underline
5. Text should be still selected. Press Delete key

Result:
In element's path:
Webkit shows "body p b" (#8438),
Opera and IE show "body p strong"
and if you start typing the text will be bold which means that formatting is not removed.
In Firefox (just like in Word) formatting is removed.

The same thing also applies to:
Bold, underline, italic, strike, sub, sup, Font Size, Paragraph Format and Styles dropdown lists.

The only exception from this rule are inline styles from Styles dropdown (E.g. Marker yellow.) which are removed on pressing Delete key in Webkit.