Initial support for tag cloud
parameterize tag cloud + enable it in community and collection home
move tag cloud html code to a separate file
resolve some fixes regarding the discovery configuration in tag cloud
enable tag cloud in browsing
url encode tag cloud's links
url encode tag cloud's links (again!)
add comments + configure browse tag cloud
minor change in configuration comments
Remove GreekNameComparator (as never used) and revert facet limit for subject facet
Separate UI from API (add classes to tag cloud so as to configure appearance from style files and not the configuration ones)
fix typos
Merge pull request #701 from helix84/DS-1227-JSPUI-tagcloud

DS-1227: Tag cloud for any browse index or Discovery facet (JSPUI only)