doc: contributing.md: add a line telling to update the authors list
Merge pull request #134 from franciscod/doc-contributing-authors

doc: contributing.md: add a line telling to update the authors list
add prerequisite steps for installing openage on Fedora 20
Merge pull request #132 from miartad/master

add prerequisite steps for installing openage on Fedora 20
misc: add F1 keybinding, toggles hud drawing