doc/conf.py, doc/index.rst:
  * Add and adapt a Sphinx skeleton for the manual.
doc/arcinfosys.rst:
  * Document the infosys probes.
README.rst -> doc/arcce.rst:
  * Move the ARC-CE probe documentation to the manual.
README.rst:
  * Describe how to build the manual and drop outdated note.

git-svn-id: https://svn.nordugrid.org/repos/nordugrid/nagios/trunk@23155 abde3d5b-3823-4793-b0f1-72698fa29e81