Fix for installation error on latest raspbian (2014-01-07)

Hi,

this commit fixes an error produced when installing. Specifically, against the raspbian-2014-01-07 image, the execution of 

    apt-get install .. watchdog

produces the following error :

    insserv: warning: script 'mathkernel' missing LSB tags and overrides
    insserv: There is a loop between service watchdog and mathkernel if stopped
    insserv:  loop involving service mathkernel at depth 2
    insserv:  loop involving service watchdog at depth 1
    insserv: Stopping mathkernel depends on watchdog and therefore on system facility `$all' which can not be true!
    insserv: exiting now without changing boot order!
    update-rc.d: error: insserv rejected the script header
    dpkg: error processing watchdog (--configure):
     subprocess installed post-installation script returned error exit status 1
    Processing triggers for python-support ...
    Processing triggers for menu ...
    Errors were encountered while processing:
     watchdog