Added a couple of using directives to clean up type declations a bit.
Added a couple of using directives to clean up type declations a bit.

StevenJiang2015/AutoFixture,StevenJiang2015/AutoFixture,olegsych/AutoFixture,dlongest/AutoFixture,adamchester/AutoFixture,mrinaldi/AutoFixture,hackle/AutoFixture,Pvlerick/AutoFixture,amarant/AutoFixture,yuva2achieve/AutoFixture,sergeyshushlyapin/AutoFixture,dcastro/AutoFixture,dcastro/AutoFixture,adamchester/AutoFixture,sean-gilliam/AutoFixture,dlongest/AutoFixture,sbrockway/AutoFixture,mrinaldi/AutoFixture,AutoFixture/AutoFixture,hackle/AutoFixture,amarant/AutoFixture,yuva2achieve/AutoFixture,olegsych/AutoFixture,zvirja/AutoFixture,sergeyshushlyapin/AutoFixture,sbrockway/AutoFixture