* [Support Center/Aesthetics] Made minor cosmetic improvements to the default Support Center stylesheet: removed unnecessary borders and lines; improved button styles; added more padding to content, lists, and sidebars; added more padding to headings; removed underlines from navigation tabs; added more hover effects; stylized worklists.
* [Support Center/Knowledgebase/Search] Simplified the knowledgebase search options in the Support Center.  Previously this displayed "all words", "any words", and "phrase".  Cerb will now attempt to determine this automatically like it does on the worker side.
* [CHD-3687] [Support Center/History] The Support Center can now be configured to display any combination of fields and custom fields as columns on the Ticket History worklist.  For example, this makes it possible to share the value of fields (e.g. owner, priority, first response time) with clients.  Previously, the columns on this worklist were limited to the bare minimum (subject, last wrote, updated).
* [Support Center/History] In the Support Center, when the 'Subject' field is explicitly configured as a column then the worklist will display with records on a single row.  Otherwise, the subject is displayed on its own line to make more room available for other columns.
[Community Portals] As a convenience, DAO_CommunityToolProperty ::get() and ::set() can automatically json_decode() and json_encode() the provided values.  This is controlled by a new argument.
* [Support Center/Knowledgebase] The Support Center can now be configured to display any combination of fields and custom fields as columns on Knowledgebase worklists.
* [Support Center/Knowledgebaae] In the Support Center, when the 'Title' field is explicitly configured as a knowledgebase column then the worklist will display with records on a single row.  Otherwise, the title is displayed on its own line to make more room available for other columns.
6.7-dev checkpoint