gomrt: split parsing and sending into different goroutines
gomrt: split parsing and sending into different goroutines

another performance improvement.

[before]
$ time gomrt -i rib.20150617.2000
gomrt -i /vagrant/rib.20150617.2000  48.98s user 149.40s system 97% cpu
3:24.30 total

[after]
$ time gomrt -i rib.20150617.2000
gomrt -i /vagrant/rib.20150617.2000  30.57s user 99.59s system 96% cpu
2:15.27 total

Signed-off-by: ISHIDA Wataru <15703620d0b11e835ab4f34ebf88f2f40cce783e@lab.ntt.co.jp>

postfix/gobgp,a16/gobgp,tamihiro/gobgp,ishidawataru/gobgp,osrg/gobgp,h-naoto/gobgp,ishidawataru/gobgp,a16/gobgp,j-kato/gobgp,Dipsingh/gobgp,YujiOshima/gobgp,a16/gobgp,a16/gobgp,Dipsingh/gobgp,tamihiro/gobgp,ishidawataru/gobgp,a16/gobgp,fujita/gobgp,tamihiro/gobgp,tamihiro/gobgp,ramrunner/gobgp,postfix/gobgp,fujita/gobgp,postfix/gobgp,a16/gobgp,h-naoto/gobgp,a16/gobgp,fujita/gobgp,YujiOshima/gobgp,osrg/gobgp,j-kato/gobgp,osrg/gobgp,j-kato/gobgp,ramrunner/gobgp,osrg/gobgp,h-naoto/gobgp,ramrunner/gobgp,Dipsingh/gobgp,YujiOshima/gobgp,fujita/gobgp