Perform route target filtering check after more basic checks
Perform route target filtering check after more basic checks

For iBGP, the split horizon check is simpler than RTF check.
For eBGP, the AS path loop check is simpler than RTF check.

Change-Id: Id8ea045d7c0f33d9b2f8786132ae21568c06c586
Partial-Bug: 1428755

DreamLab/contrail-controller,numansiddique/contrail-controller,vmahuli/contrail-controller,hthompson6/contrail-controller,vpramo/contrail-controller,hthompson6/contrail-controller,facetothefate/contrail-controller,facetothefate/contrail-controller,DreamLab/contrail-controller,sajuptpm/contrail-controller,tcpcloud/contrail-controller,sajuptpm/contrail-controller,sajuptpm/contrail-controller,hthompson6/contrail-controller,codilime/contrail-controller,eonpatapon/contrail-controller,facetothefate/contrail-controller,nischalsheth/contrail-controller,numansiddique/contrail-controller,tcpcloud/contrail-controller,rombie/contrail-controller,sajuptpm/contrail-controller,reiaaoyama/contrail-controller,vmahuli/contrail-controller,codilime/contrail-controller,codilime/contrail-controller,eonpatapon/contrail-controller,DreamLab/contrail-controller,DreamLab/contrail-controller,reiaaoyama/contrail-controller,hthompson6/contrail-controller,eonpatapon/contrail-controller,tcpcloud/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,nischalsheth/contrail-controller,hthompson6/contrail-controller,eonpatapon/contrail-controller,vmahuli/contrail-controller,eonpatapon/contrail-controller,facetothefate/contrail-controller,rombie/contrail-controller,reiaaoyama/contrail-controller,vpramo/contrail-controller,reiaaoyama/contrail-controller,tcpcloud/contrail-controller,DreamLab/contrail-controller,vmahuli/contrail-controller,tcpcloud/contrail-controller,sajuptpm/contrail-controller,codilime/contrail-controller,vmahuli/contrail-controller,eonpatapon/contrail-controller,facetothefate/contrail-controller,reiaaoyama/contrail-controller,vpramo/contrail-controller,sajuptpm/contrail-controller,numansiddique/contrail-controller,rombie/contrail-controller,vpramo/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,codilime/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,codilime/contrail-controller,tcpcloud/contrail-controller,nischalsheth/contrail-controller,numansiddique/contrail-controller,rombie/contrail-controller,rombie/contrail-controller,vpramo/contrail-controller,numansiddique/contrail-controller,nischalsheth/contrail-controller