Implement support of 'insmod' and 'modprobe' commands into ModuleManager

Implement support of 'insmod' and 'modprobe' commands into ModuleManager

Module manager has been enhanced to support both 'insmod' and 'modprobe'
commands for kernel module insertion. In case, that .ko suffix is detected
then insmod will be used otherwise modprobe will be called. This allows
user to specify full path to each module. For example vanilla ovs module
can be defined as "OVS_DIR_VANILLA + 'datapath/linux/openvswitch.ko'"
to load kernel module matching OVS vanilla source tree version.

Change-Id: Ib8d16eca84449ad34d6b307ab836f58d2f0d341b
JIRA: VSPERF-116
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Billy O Mahony <billy.o.mahony@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Brian Castelli <brian.castelli@spirent.com>