[Libreoffice] [REVIEW] Use different Windows registry keys than OOo

Hi all,

This commit fixes the problems with file associations when you have
OOo and LibO installed side by side on Windows. Today, as most of the
the registry keys are shared, they are deleted or overwriten when you
install or uninstall either OOo or LibO, making the Windows
integration broken.

A common scenario for our users, like this one, will leave the LibO
installation broken if the patch is not applied:

1. OpenOffice.org 3.2.1 installed on the system
2. Install LibO 3.3, the user likes it!
3. Uninstall OpenOffice.org 3.2.1

Result: Integration with Windows broken. The user doesn't understand
the problem and complains to us.

Commit (master):
http://cgit.freedesktop.org/libreoffice/bootstrap/commit/?id=aac47dc11beea0dda755dbf7e9fa973d367998c5

Please cherry pick for libreoffice-3-3 or even libreoffice-3-3-0.

-- 
Jesús Corrius <jesus@softcatala.org>
Document Foundation founding member
Skype: jcorrius | Twitter: @jcorrius