Fix multiple default gateways reporting

Up until now there was just a default gateway per host, defining
default as going towards 0.0.0.0/0. If more than one device
received a default gateway setting, only the latest to be
configured kept its configuration as host default configuration.

Now, thanks to multiple gateways, we have a routing table for each
network, which allows us to have multiple default gateways to
report. The only issue is that /proc/net/route only reports
information for table 254, while we are using several. For this
reason, we change the implementation to use ipwrapper to get the
information from all the tables.

PatchSet 2:
- Fix calling to ipwrapper and added it to lib/vdsm/Makefile.am

PatchSet 3:
- Rebase on top of the fixes of multiple gateways.
- Split Routes fromText into parser and fromText.
- Made source use the new placement and parse method of ipwrapper.

Patch Set 4:
- Rebase the patch.

Change-Id: Iacd6328a938b955a63bbc0d5c0fb9bfcc7de6d44
Signed-off-by: Antoni S. Puimedon <asegurap@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/15890
Reviewed-by: Dan Kenigsberg <danken@redhat.com>