Update Look And Feel Settings

Updates the look and feel settings for the site or for a single space.If custom settings exist, they are updated. If no custom settings exist,then a set of custom settings is created.Note, if a theme is selected for a space, the space look and feel settingsare provided by the theme and cannot be overridden.**[Permissions](https://confluence.atlassian.com/x/_AozKw) required**:'Admin' permission for the space.