added javadoc to ProjectUser
added javadoc to ProjectUser

naver/yobi,naver/yobi,yona-projects/yona,doortts/fork-yobi,ChangsungKim/TestRepository01,yona-projects/yona,Limseunghwan/oss,naver/yobi,doortts/fork-yobi,violetag/demo,bloodybear/yona,doortts/forked-for-history,ChangsungKim/TestRepository01,brainagenet/yobi,yona-projects/yona,yona-projects/yona,ihoneymon/yobi,ahb0327/yobi,oolso/yobi,ahb0327/yobi,bloodybear/yona,Limseunghwan/oss,violetag/demo,brainagenet/yobi,bloodybear/yona,oolso/yobi,doortts/forked-for-history,ahb0327/yobi,Limseunghwan/oss,doortts/fork-yobi,ihoneymon/yobi,doortts/fork-yobi,doortts/forked-for-history,oolso/yobi,brainagenet/yobi,ihoneymon/yobi,bloodybear/yona