Update libxml2 RPM to 2.7.8+git20110708-3.20.1 for CVE-2013-0338.

Bump PKGREVISION.
Updated emulators/suse121_libxml2 to 12.1nb5
Update leaf package mikutter to 0.2.1.1141.

fixes following issues
* fail to startup or break configureation file with 3rd party plugins,
  especially on Ruby 2.0.0.
* sometimes crash on Ruby 1.9.3.
Updated net/mikutter to 0.2.1.1141