adds ucnames option

This is in response to a user on the forum who wanted page names where underscores are replaced by spaces and the first letter of each name in the page name is capitalized.  The new option is 'ucnames'.  If the 'namespacename' option is also selected in conjunction with 'ucnames', the directory names are not printed in red (wikilnk2) but in the color the external links.

Edit: needs the update:
 https://github.com/turnermm/dokuwiki-plugin-dir/commit/9cf9e4155b00b35a70926d1d347ffbf9d0333c73
which replaces missing ':' from beginnings of ids.

For an example of the result see: http://www.mturner.org/devel/doku.php?id=playground:dir