Automatically open/close inline decorations around bidi runs.

Change-Id: I69c0be501b4e1663d2f1364048a24c2db273d244
Allow env/line/paragraph breaks in the middle of 'inline' decorations.

We simply close the inline style, do the break, and then open it again.
This allows <br/> inside of <i>, for instance.

Change-Id: Iac9e3823b94f85ec959a9d0b6cfeacda830318a3