fixed specfile to include mass rebuild changelog entry
    
    - package_state: drop privs when writing available_packages data [BZ# 916685]
    - unconditionally update default.cfg on install [BZ# 858822]
    - attempt to make mock more EL5 friendly [BZ# 949616]
    - do not ignore missing dependencies [BZ# 955478]
    - set the group defined in chrootgid [BZ# 953519]
    - add the --nocheck option to mock [BZ# 1015790]
    - raise privs before deleting rpm db files in chroot [BZ# 973617]
    - clean up orphan processes even if chroot not cleaned [BZ# 972868]
    - do not remove the chroot builddir if not cleaning the chroot [BZ# 483486]
    - use root object environment in package_state plugin [BZ# 921221]
    - Pass values of --plugin-option through literal_eval [BZ# 1018359]
    - add default mode to mount in tmpfs plugin [BZ# 598257]
    - exit mockbuild.util.logOutput() when child process dies [BZ# 885405]