Update CHANGES.txt for recent commits to 2.7 and 2.6
Update CHANGES.txt for recent commits to 2.7 and 2.6

apurtell/hadoop,dennishuo/hadoop,steveloughran/hadoop,huafengw/hadoop,wenxinhe/hadoop,ctrezzo/hadoop,plusplusjiajia/hadoop,soumabrata-chakraborty/hadoop,dierobotsdie/hadoop,GeLiXin/hadoop,GeLiXin/hadoop,bitmybytes/hadoop,szegedim/hadoop,ronny-macmaster/hadoop,bitmybytes/hadoop,nandakumar131/hadoop,steveloughran/hadoop,ctrezzo/hadoop,wenxinhe/hadoop,ucare-uchicago/hadoop,GeLiXin/hadoop,WIgor/hadoop,bitmybytes/hadoop,dennishuo/hadoop,ctrezzo/hadoop,dierobotsdie/hadoop,legend-hua/hadoop,ChetnaChaudhari/hadoop,legend-hua/hadoop,Ethanlm/hadoop,979969786/hadoop,huafengw/hadoop,szegedim/hadoop,szegedim/hadoop,dennishuo/hadoop,GeLiXin/hadoop,plusplusjiajia/hadoop,dierobotsdie/hadoop,littlezhou/hadoop,Ethanlm/hadoop,ronny-macmaster/hadoop,wwjiang007/hadoop,soumabrata-chakraborty/hadoop,apurtell/hadoop,szegedim/hadoop,soumabrata-chakraborty/hadoop,apurtell/hadoop,plusplusjiajia/hadoop,bitmybytes/hadoop,mapr/hadoop-common,littlezhou/hadoop,JingchengDu/hadoop,Ethanlm/hadoop,bitmybytes/hadoop,dennishuo/hadoop,ctrezzo/hadoop,dierobotsdie/hadoop,apache/hadoop,littlezhou/hadoop,lukmajercak/hadoop,JingchengDu/hadoop,mapr/hadoop-common,GeLiXin/hadoop,WIgor/hadoop,mapr/hadoop-common,ChetnaChaudhari/hadoop,mapr/hadoop-common,wenxinhe/hadoop,Ethanlm/hadoop,WIgor/hadoop,ucare-uchicago/hadoop,wenxinhe/hadoop,dennishuo/hadoop,wwjiang007/hadoop,JingchengDu/hadoop,dierobotsdie/hadoop,mapr/hadoop-common,legend-hua/hadoop,apurtell/hadoop,apache/hadoop,ChetnaChaudhari/hadoop,bitmybytes/hadoop,wenxinhe/hadoop,ChetnaChaudhari/hadoop,ucare-uchicago/hadoop,apache/hadoop,JingchengDu/hadoop,ucare-uchicago/hadoop,979969786/hadoop,GeLiXin/hadoop,steveloughran/hadoop,plusplusjiajia/hadoop,ucare-uchicago/hadoop,JingchengDu/hadoop,huafengw/hadoop,WIgor/hadoop,JingchengDu/hadoop,xiao-chen/hadoop,steveloughran/hadoop,ronny-macmaster/hadoop,ronny-macmaster/hadoop,apache/hadoop,xiao-chen/hadoop,soumabrata-chakraborty/hadoop,xiao-chen/hadoop,wwjiang007/hadoop,lukmajercak/hadoop,xiao-chen/hadoop,nandakumar131/hadoop,soumabrata-chakraborty/hadoop,979969786/hadoop,nandakumar131/hadoop,ronny-macmaster/hadoop,wenxinhe/hadoop,ctrezzo/hadoop,plusplusjiajia/hadoop,apache/hadoop,wwjiang007/hadoop,979969786/hadoop,mapr/hadoop-common,plusplusjiajia/hadoop,Ethanlm/hadoop,ronny-macmaster/hadoop,nandakumar131/hadoop,ChetnaChaudhari/hadoop,dierobotsdie/hadoop,bitmybytes/hadoop,ronny-macmaster/hadoop,wwjiang007/hadoop,ctrezzo/hadoop,mapr/hadoop-common,979969786/hadoop,GeLiXin/hadoop,huafengw/hadoop,lukmajercak/hadoop,szegedim/hadoop,plusplusjiajia/hadoop,dennishuo/hadoop,steveloughran/hadoop,wenxinhe/hadoop,nandakumar131/hadoop,szegedim/hadoop,dennishuo/hadoop,legend-hua/hadoop,xiao-chen/hadoop,979969786/hadoop,ChetnaChaudhari/hadoop,littlezhou/hadoop,huafengw/hadoop,apurtell/hadoop,steveloughran/hadoop,lukmajercak/hadoop,steveloughran/hadoop,ucare-uchicago/hadoop,ChetnaChaudhari/hadoop,wwjiang007/hadoop,huafengw/hadoop,legend-hua/hadoop,apache/hadoop,apurtell/hadoop,soumabrata-chakraborty/hadoop,wwjiang007/hadoop,lukmajercak/hadoop,legend-hua/hadoop,apurtell/hadoop,ucare-uchicago/hadoop,apache/hadoop,nandakumar131/hadoop,littlezhou/hadoop,ctrezzo/hadoop,nandakumar131/hadoop,WIgor/hadoop,soumabrata-chakraborty/hadoop,WIgor/hadoop,littlezhou/hadoop,WIgor/hadoop,legend-hua/hadoop,JingchengDu/hadoop,Ethanlm/hadoop,lukmajercak/hadoop,huafengw/hadoop,szegedim/hadoop,lukmajercak/hadoop,xiao-chen/hadoop,dierobotsdie/hadoop,xiao-chen/hadoop,littlezhou/hadoop,Ethanlm/hadoop,979969786/hadoop