[install-guide] (4 commits) ...Merge branch 'master' of ssh://git.fedorahosted.org/git/docs/install-guide

[pbokoc]

Summary of changes:

  150a09b... Update references to reflect DNF as the default package man (*)
  9cd0050... use unusable ks, and inst.stage2 to allow generic repo reso (*)
  9ba26d9... PXE Improvements (*)
  b6aba0c... Merge branch 'master' of ssh://git.fedorahosted.org/git/doc (*)

(*) This commit already existed in another branch; no separate mail sent