Merge branch 'master' of github.com:studip/PluginMarket

PluginMarket.class.php

assets/pluginmarket.less

controllers/myplugins.php

controllers/presenting.php

controllers/update.php

plugin.manifest

views/approving/review.php

views/myplugins/_edit_images.php

views/myplugins/delete.php

views/myplugins/edit.php

views/myplugins/edit_images.php

views/myplugins/edit_release.php

views/presenting/details.php

views/presenting/follow_release.php

views/presenting/propose_usage.php

views/presenting/review.php

views/tools/sidebar_graphics_generator.php

views/update/save_usage.php

views/update/usage.php