Merge pull request #37 from infirit/1.6

Cherrypick usefull commits from master
add support for rar-5.0x
package installer: don't display an error message if the user cancelled the operation
engrampa does not build without packagekit

https://bugzilla.gnome.org/show_bug.cgi?id=634356
Fix Sun GNOME Documentation Team references
 fixed error when creating zip archives with files starting with an hyphen
zip: fixed -- position for the extraction command, added for list and test