Consistent update for bob() and livePreview().

* readme.md : Little typo fix.
* views/view.index.php : Changed the displayed row  from body to
body_processed. See notes for info.
* views/view.content.php : Same as views/view.index.php.
* views/admin.contents.php : inserted an hidden input that holds the
processed body text and is populated using jQuery on writing.
* core/class.contents.php : Added body_processed row in Add and Edit
Content.
* views/js/main.js : bob() and livePreview() update. Now, instead of
replace the textarea value, it updates the div.preview and keep the bob
syntax unchanged. In this way it's easier to update and/or edit the
content later.

Notes:
Committed the updated __db.sql. Added a row in vdcontents to hold the
processed (html) contents. In this way the non-processed (bob syntax) is
available for edits.