Merge pull request #359 from adrianschroeter/master

- Require at least one instsource plugin via generic provide
- Fixed kiwi --info <image-description> --select repo-patterns
  * For SLE12 and Factory the new pattern system is based on
    rpm packages. Thus the solvable metadata has changed. This
    commit allows to get the patterns from the repo for the old
    and the new pattern system
- Fixed KIWIGlobals::downloadFile function
  * quote shell escape chars because the url is passed to lwp-download
  * fix regexp extracting url credentials. the expression matches too
    much of a file path in the first ancor
  * fixed cleanup of files downloaded if solvable creation out of
    this data has failed. Don't leave waste of data in this case
- fix missing dependency to grub(1) for vmx and oem builds