Make icon tag accept options

Allow passing options to the icon tag, e.g. title, which will be
displayed on the icon hover.
Use icon_tag helper in proposal_show
Separate the cluster related pacemaker-crowbar proxies
Renamed i18n file, added quotes and copyright
Merge pull request #1032 from tboerger/feature/i18n-rename

Renamed i18n file, added quotes and copyright
Merge pull request #1026 from bkutil/pacemaker_proxy

Separate the cluster related pacemaker-crowbar proxies
Merge pull request #1018 from bkutil/icon_tag_accepts_options

Make icon tag accept options
Merge pull request #1019 from bkutil/use_new_icon_helper

Use icon_tag helper in proposal_show