[R-wiki] New structure is implemented

[Philippe Grosjean]

Hello,

For the second time, I have reworked everything, implementing the 
proposed structure. The page change histories are lost (well, I have a 
backup on my machine), because I had to start with a fresh Wiki.

Could you check if this is fine? I need the final structure for 8-10 
days from now. At that time, I will start the definitive R Wiki on a 
dedicated server (still a temporary server, but now, totally dedicated 
to the R Wiki -should be faster- and with the final IP address).

In the meantime, I will work on the Wiki engine itself. I have a couple 
of additional plugins, a refined R syntax highlighter, etc. to inject in 
the Wiki engine.

Please, report any fealure or misfunctionment. We start now the 
beta-test of the final Wiki engine (well, when all the changes I made on 
  my local copy will be implemented on the prototype, that is, in a 
couple of days).

Thank you for your help.
Best,

Philippe Grosjean