controller/dispatcher: allow handler that accepts any event type
controller/dispatcher: allow handler that accepts any event type

This type of handler will be used by event dumper application.

Signed-off-by: Isaku Yamahata <4b3abd66323411eeceff090ab3754dd766fc4b25@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <93dac1fe9c4b2a3957982200319981492ad4976e@lab.ntt.co.jp>

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