doc: Document expect_string*()
doc: Document expect_string*()

nuumio/cmocka,dsch/cmocka,nuumio/cmocka,jamesmunns/CMocka,Odie/cmocka,dsch/cmocka,JonathonReinhart/cmocka,aleksandr-vin/cmock,jhrozek/cmocka,tyc/cmocka,tyc/cmocka,VladimirTyrin/cmocka,jamesmunns/CMocka,JonathonReinhart/cmocka,wingyplus/cmocka,linuxmaniac/cmocka,clibs/cmocka,jschmidlapp/cmocka,jhrozek/cmocka,lsjostro/cmocka,wingyplus/cmocka,Odie/cmocka,Odie/cmocka,aleksandr-vin/cmock,jschmidlapp/cmocka,jschmidlapp/cmocka,nuumio/cmocka,clibs/cmocka,lsjostro/cmocka,tyc/cmocka,chadversary/cmocka,chadversary/cmocka,VladimirTyrin/cmocka,linuxmaniac/cmocka,jhrozek/cmocka