This patch adds some missing entries/hotkey descriptions into the menus.
See http://projects.blender.org/tracker/index.php?func=detail&aid=4655&group_id=9&atid=125

It also fixes the passepartout entry found in the toolbox render menu.

Changes:
- Added missing entries for preview render into the headers render menu and the spacebar render menu.
- Added hotkey descriptions for "Set border" and "Anim" to the toolbox render menu
- The passepartout option in toolbox render menu didn't work anymore. This is because it was changed to be a camera option. Updated this function to use the new camera option CAM_SHOWPASSEPARTOUT.

Disclaimer:
This is my first patch so if anything in there is silly, please don't kill me! :)

Cheers,
Ralf