xbmc-pvr-addons: update to xbmc-pvr-addons-af29425
vdr-plugin-vnsiserver: update to vdr-plugin-vnsiserver-af29425
buildsystem: support for older git versions

As older git versions don't support "git rev-list --count" run it with wc instead if needed
buildsystem: support for automated package installation for RedHat (and clones)
xbmc: update to xbmc-13.alpha-536cf62
Merge pull request #2901 from at-visions/centos

Support for building on RedHat/CentOS