[STONITH] Disable ipmilan by default
According to Sean Reifschneider the ipmilan stonith module seems
to be in cronically bad health.

This patch provides a configure option to enable compiling ipmilan,
which is now disabled by default.

Cc: Sean Reifschneider <jafo@tummy.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

--HG--
extra : convert_revision : 11b9a169980a512fad5f4799b0729aaa049fabe0