Update NEWS and ChangeLog for 1.0.rc6
    
    	* ChangeLog: Update this automatically using "make
    	update-changelog".
    	* NEWS: update this by editing the output of 'git shortlog
    	libabigail-1.0.rc5..HEAD'.
    
    Signed-off-by: Dodji Seketeli <dodji@redhat.com>