adapt rakefile to use yast rake config
fixed the "run" task

args[:foo] cannot be assigned to. well it can but it silently ignores
the assignment :(
args is Rake::TaskArguments whose method_missing hides the error

http://ruby-doc.org/stdlib-2.0.0/libdoc/rake/rdoc/Rake/TaskArguments.html
changes
Merge pull request #4 from yast/fix-run-taskarguments

Fixed `rake run` to work and `rake run[foo]` to really use the local files.
Merge branch 'master' of github.com:yast/yast-rake