of1.2: add common field_parser for MT* classes
of1.2: add common field_parser for MT* classes

Most of MT* classes can use this helper classmethod.

We get value and mask values but don't set them to an instance. It's
done later.

Signed-off-by: FUJITA Tomonori <93dac1fe9c4b2a3957982200319981492ad4976e@lab.ntt.co.jp>

John-Lin/ryu,fkakuma/ryu,TakeshiTseng/ryu,citrix-openstack/build-ryu,umkcdcrg01/ryu_openflow,jalilm/ryu,habibiefaried/ryu,ntts-clo/mld-ryu,zyq001/ryu,Tejas-Subramanya/RYU_MEC,diogommartins/ryu,samrussell/ryu,citrix-openstack-build/ryu,jkoelker/ryu,Tejas-Subramanya/RYU_MEC,lzppp/mylearning,elahejalalpour/ELRyu,diogommartins/ryu,alyosha1879/ryu,darjus-amzn/ryu,yamt/ryu,Tesi-Luca-Davide/ryu,OpenState-SDN/ryu,elahejalalpour/ELRyu,darjus-amzn/ryu,ntts-clo/ryu,ttsubo/ryu,fkakuma/ryu,muzixing/ryu,zyq001/ryu,fujita/ryu,takahashiminoru/ryu,lzppp/mylearning,muzixing/ryu,ttsubo/ryu,sivaramakrishnansr/ryu,lsqtongxin/ryu,OpenState-SDN/ryu,castroflavio/ryu,jalilm/ryu,gareging/SDN_Framework,StephenKing/ryu,gareging/SDN_Framework,haniehrajabi/ryu,yamt/ryu,ntts-clo/ryu,iwaseyusuke/ryu,fujita/ryu,diogommartins/ryu,ysywh/ryu,StephenKing/ryu,torufuru/oolhackathon,haniehrajabi/ryu,John-Lin/ryu,citrix-openstack-build/ryu,TakeshiTseng/ryu,darjus-amzn/ryu,jalilm/ryu,umkcdcrg01/ryu_openflow,TakeshiTseng/ryu,ynkjm/ryu,Tesi-Luca-Davide/ryu,lagopus/ryu-lagopus-ext,hisaharu/ryu,openvapour/ryu,StephenKing/summerschool-2015-ryu,mikhaelharswanto/ryu,Tejas-Subramanya/RYU_MEC,ykaneko/ryu,StephenKing/ryu,alyosha1879/ryu,yamada-h/ryu,iwaseyusuke/ryu,jalilm/ryu,jkoelker/ryu,StephenKing/ryu,ysywh/ryu,zyq001/ryu,gareging/SDN_Framework,Tesi-Luca-Davide/ryu,openvapour/ryu,lagopus/ryu-lagopus-ext,ysywh/ryu,zangree/ryu,OpenState-SDN/ryu,diogommartins/ryu,pichuang/ryu,citrix-openstack/build-ryu,torufuru/OFPatchPanel,jalilm/ryu,ynkjm/ryu,alanquillin/ryu,torufuru/OFPatchPanel,lagopus/ryu-lagopus-ext,StephenKing/summerschool-2015-ryu,pichuang/ryu,jazzmes/ryu,habibiefaried/ryu,TakeshiTseng/ryu,jazzmes/ryu,lzppp/mylearning,fujita/ryu,openvapour/ryu,Zouyiran/ryu,ttsubo/ryu,fkakuma/ryu,Zouyiran/ryu,darjus-amzn/ryu,elahejalalpour/ELRyu,evanscottgray/ryu,lzppp/mylearning,Tesi-Luca-Davide/ryu,gopchandani/ryu,shinpeimuraoka/ryu,castroflavio/ryu,hisaharu/ryu,gopchandani/ryu,sivaramakrishnansr/ryu,alyosha1879/ryu,ynkjm/ryu,zangree/ryu,StephenKing/summerschool-2015-ryu,gopchandani/ryu,lagopus/ryu-lagopus-ext,diogommartins/ryu,alyosha1879/ryu,John-Lin/ryu,muzixing/ryu,Tejas-Subramanya/RYU_MEC,torufuru/oolhackathon,haniehrajabi/ryu,elahejalalpour/ELRyu,John-Lin/ryu,sivaramakrishnansr/ryu,zyq001/ryu,pichuang/ryu,elahejalalpour/ELRyu,takahashiminoru/ryu,fkakuma/ryu,darjus-amzn/ryu,Zouyiran/ryu,OpenState-SDN/ryu,takahashiminoru/ryu,evanscottgray/ryu,ynkjm/ryu,zangree/ryu,gopchandani/ryu,Tejas-Subramanya/RYU_MEC,zangree/ryu,haniehrajabi/ryu,iwaseyusuke/ryu,osrg/ryu,jazzmes/ryu,mikhaelharswanto/ryu,jkoelker/ryu,yamt/ryu,ntts-clo/mld-ryu,takahashiminoru/ryu,openvapour/ryu,hisaharu/ryu,sivaramakrishnansr/ryu,lsqtongxin/ryu,lzppp/mylearning,ttsubo/ryu,iwaseyusuke/ryu,alanquillin/ryu,torufuru/oolhackathon,gareging/SDN_Framework,ykaneko/ryu,pichuang/ryu,ysywh/ryu,takahashiminoru/ryu,ttsubo/ryu,openvapour/ryu,shinpeimuraoka/ryu,sivaramakrishnansr/ryu,Zouyiran/ryu,habibiefaried/ryu,Tesi-Luca-Davide/ryu,ysywh/ryu,lsqtongxin/ryu,haniehrajabi/ryu,iwaseyusuke/ryu,yamt/ryu,alanquillin/ryu,shinpeimuraoka/ryu,samrussell/ryu,TakeshiTseng/ryu,habibiefaried/ryu,evanscottgray/ryu,shinpeimuraoka/ryu,osrg/ryu,osrg/ryu,fkakuma/ryu,shinpeimuraoka/ryu,fujita/ryu,lsqtongxin/ryu,osrg/ryu,fujita/ryu,lsqtongxin/ryu,alanquillin/ryu,alanquillin/ryu,umkcdcrg01/ryu_openflow,StephenKing/ryu,StephenKing/summerschool-2015-ryu,hisaharu/ryu,muzixing/ryu,zyq001/ryu,unifycore/ryu,o3project/ryu-oe,StephenKing/summerschool-2015-ryu,ynkjm/ryu,castroflavio/ryu,zangree/ryu,umkcdcrg01/ryu_openflow,yamt/ryu,muzixing/ryu,Zouyiran/ryu,John-Lin/ryu,lagopus/ryu-lagopus-ext,hisaharu/ryu,yamada-h/ryu,habibiefaried/ryu,unifycore/ryu,o3project/ryu-oe,umkcdcrg01/ryu_openflow,gareging/SDN_Framework,osrg/ryu,OpenState-SDN/ryu,pichuang/ryu,gopchandani/ryu