[metastore] Replace 'None' with 'NULL' in table sample
[metastore] Replace 'None' with 'NULL' in table sample

https://github.com/cloudera/hue/pull/144

jounex/hue,fangxingli/hue,ChenJunor/hue,xq262144/hue,kawamon/hue,jounex/hue,fangxingli/hue,abhishek-ch/hue,erickt/hue,sanjeevtripurari/hue,jjmleiro/hue,hdinsight/hue,epssy/hue,jayceyxc/hue,GitHublong/hue,vitan/hue,erickt/hue,Peddle/hue,javachengwc/hue,todaychi/hue,MobinRanjbar/hue,x303597316/hue,ChenJunor/hue,javachengwc/hue,vmax-feihu/hue,xq262144/hue,yoer/hue,azureplus/hue,lumig242/Hue-Integration-with-CDAP,todaychi/hue,azureplus/hue,MobinRanjbar/hue,x303597316/hue,nvoron23/hue,GitHublong/hue,dulems/hue,xq262144/hue,erickt/hue,cloudera/hue,jayceyxc/hue,hdinsight/hue,kawamon/hue,GitHublong/hue,hdinsight/hue,jounex/hue,vitan/hue,cloudera/hue,yongshengwang/hue,kawamon/hue,ahmed-mahran/hue,jjmleiro/hue,x303597316/hue,cloudera/hue,vmax-feihu/hue,todaychi/hue,xiangel/hue,ahmed-mahran/hue,jounex/hue,sanjeevtripurari/hue,rahul67/hue,jjmleiro/hue,azureplus/hue,kawamon/hue,abhishek-ch/hue,sanjeevtripurari/hue,nvoron23/hue,nvoron23/hue,MobinRanjbar/hue,kawamon/hue,kawamon/hue,cloudera/hue,kawamon/hue,Peddle/hue,rahul67/hue,abhishek-ch/hue,hdinsight/hue,jayceyxc/hue,pratikmallya/hue,jjmleiro/hue,xiangel/hue,javachengwc/hue,xq262144/hue,yoer/hue,yongshengwang/hue,mapr/hue,cloudera/hue,lumig242/Hue-Integration-with-CDAP,vmax-feihu/hue,nvoron23/hue,lumig242/Hue-Integration-with-CDAP,fangxingli/hue,ChenJunor/hue,erickt/hue,vitan/hue,mapr/hue,yongshengwang/hue,jayceyxc/hue,kawamon/hue,ahmed-mahran/hue,pratikmallya/hue,sanjeevtripurari/hue,yoer/hue,xq262144/hue,azureplus/hue,pratikmallya/hue,todaychi/hue,erickt/hue,yoer/hue,kawamon/hue,jjmleiro/hue,ChenJunor/hue,ChenJunor/hue,vitan/hue,cloudera/hue,hdinsight/hue,mapr/hue,lumig242/Hue-Integration-with-CDAP,vmax-feihu/hue,erickt/hue,jayceyxc/hue,yongshengwang/hue,fangxingli/hue,cloudera/hue,javachengwc/hue,jjmleiro/hue,todaychi/hue,GitHublong/hue,azureplus/hue,epssy/hue,lumig242/Hue-Integration-with-CDAP,cloudera/hue,cloudera/hue,sanjeevtripurari/hue,cloudera/hue,nvoron23/hue,epssy/hue,abhishek-ch/hue,xq262144/hue,sanjeevtripurari/hue,fangxingli/hue,kawamon/hue,rahul67/hue,epssy/hue,x303597316/hue,todaychi/hue,dulems/hue,pratikmallya/hue,jounex/hue,jayceyxc/hue,nvoron23/hue,xiangel/hue,todaychi/hue,jounex/hue,rahul67/hue,Peddle/hue,vmax-feihu/hue,cloudera/hue,rahul67/hue,yoer/hue,fangxingli/hue,jounex/hue,mapr/hue,ChenJunor/hue,mapr/hue,jounex/hue,xq262144/hue,hdinsight/hue,dulems/hue,azureplus/hue,erickt/hue,vitan/hue,vmax-feihu/hue,yoer/hue,xiangel/hue,x303597316/hue,epssy/hue,GitHublong/hue,xq262144/hue,cloudera/hue,kawamon/hue,ahmed-mahran/hue,vmax-feihu/hue,javachengwc/hue,xiangel/hue,ahmed-mahran/hue,x303597316/hue,javachengwc/hue,jjmleiro/hue,xiangel/hue,lumig242/Hue-Integration-with-CDAP,yongshengwang/hue,vitan/hue,yongshengwang/hue,yoer/hue,xq262144/hue,MobinRanjbar/hue,pratikmallya/hue,todaychi/hue,cloudera/hue,rahul67/hue,mapr/hue,jayceyxc/hue,jjmleiro/hue,Peddle/hue,dulems/hue,MobinRanjbar/hue,vitan/hue,lumig242/Hue-Integration-with-CDAP,ChenJunor/hue,cloudera/hue,todaychi/hue,abhishek-ch/hue,javachengwc/hue,xiangel/hue,cloudera/hue,Peddle/hue,abhishek-ch/hue,ahmed-mahran/hue,ahmed-mahran/hue,javachengwc/hue,jayceyxc/hue,epssy/hue,epssy/hue,kawamon/hue,jjmleiro/hue,mapr/hue,Peddle/hue,MobinRanjbar/hue,kawamon/hue,rahul67/hue,sanjeevtripurari/hue,vmax-feihu/hue,ChenJunor/hue,Peddle/hue,azureplus/hue,cloudera/hue,yoer/hue,kawamon/hue,MobinRanjbar/hue,abhishek-ch/hue,xiangel/hue,abhishek-ch/hue,yongshengwang/hue,dulems/hue,epssy/hue,jayceyxc/hue,Peddle/hue,GitHublong/hue,hdinsight/hue,kawamon/hue,Peddle/hue,nvoron23/hue,cloudera/hue,kawamon/hue,yongshengwang/hue,dulems/hue,pratikmallya/hue,erickt/hue,x303597316/hue,cloudera/hue,azureplus/hue,rahul67/hue,ahmed-mahran/hue,pratikmallya/hue,nvoron23/hue,kawamon/hue,MobinRanjbar/hue,dulems/hue,sanjeevtripurari/hue,kawamon/hue,fangxingli/hue,fangxingli/hue,GitHublong/hue,lumig242/Hue-Integration-with-CDAP,dulems/hue,hdinsight/hue,pratikmallya/hue,GitHublong/hue,vitan/hue,x303597316/hue,lumig242/Hue-Integration-with-CDAP