Reviewed-by: iustinp

- Move symlink to “ganeti” to top dir
- Add ganeti.config_unittest.py to tests to be run
- Make sure everything is built before tests are run

Reviewed-by: iustinp

Reviewed-by: iustinp, ultrotter

Reviewed-by: iustin

Reviewed-by: iustin

Reviewed-by: iustinp

- Add Makefile in doc/examples/

Reviewed-by: schreiberal

Changes:
  - add note about installing the cron job
  - add an example cron job file and modify top-level Makefile.am to put
    it into the archive
  - modify the tutorial with information about setting a reasonable
    number of minors for DRBD
  - add note about installing on 32-bit the xen libc

Reviewed-by: imsnah

It fixes the main Makefile.am to create $localstatedir/{lib,log}/ganeti.
It fixes the testing Makefile.am after the rename fake_config.py ->
mocks.py.  It strips the output of "ip link show" to have a nicer output
if the master netdev does not exist.