APEXCORE-569 : Fixing javadoc errors with jdk8
APEXCORE-569 : Fixing javadoc errors with jdk8

tushargosavi/apex-core,tushargosavi/incubator-apex-core,tushargosavi/apex-core,vrozov/incubator-apex-core,tushargosavi/apex-core,apache/incubator-apex-core,vrozov/incubator-apex-core,vrozov/apex-core,vrozov/incubator-apex-core,tushargosavi/incubator-apex-core,apache/incubator-apex-core,tushargosavi/incubator-apex-core,vrozov/apex-core,apache/incubator-apex-core,vrozov/apex-core