ZCTextIndex  Add: Create a new ZCTextIndex

    Description
    
        A ZCTextIndex is an index for performing full text searches over
        bodies of text. It includes the following features:
        
        - Boolean query operators with parenthetical grouping
        
        - Globbing (partial word) and phrase matching
        
        - Two selectable relevance scoring algorithms
        
        ZCTextIndex is designed as a replacement for standard TextIndex, and
        has several advantages over it.
        
    Controls
    
        'Id' -- The id of the ZCTextIndex, must be unique for this ZCatalog.
        
        'Field Name' -- The name of the field (object attribute) to be indexed.
        
        'Ranking Strategy'
        
        - **Okapi BM25 Rank** A relevance scoring technique that seems to
          work well when the document text is considerably longer than the
          query string, which is often the case with user specified query
          strings.

        - **Cosine Measure** A relevance scoring technique derived from the
          "*Managing Gigabytes*":http://www.cs.mu.oz.au/mg/ book. It seems
          to work best when the queries are similar in size and content to
          the text they are searching.
             
        'Lexicon' -- The ZCTextIndex Lexicon to be used by this ZCTextIndex.
                     Lexicons process and store the words from the text and
                     help in processing queries. You must define a ZCTextIndex
                     Lexicon before you can create a ZCTextIndex. Several
                     ZCTextIndexes can share the same Lexicon if desired.