in index, but get them on demand from doc.

Removed vestiges of InvertedIndex.

find 'Application' it would (on bsdi, anyway) raise AttributeError and
only KeyError was being caught...

non-threaded environments.

Took stab at expression documentation.

- Changed user exceptions to include HTML markup.
- Got rid of regular expression input types.

Updated __call__ so queries can be used in documents.

Changed name of acquire method to aq_acquire.  Explicit.acquire is
an alias.

Added latest validation rules.

Added template dict to override arguments.

  - Available for Impleicit and Explicit,

  - Does not filter names with leading underscore,

  - Accepts optional 'filter' and 'extra' arguments.  If 'filter'
    is provided, then it must be a callable object and it is
    called with four arguments:

      inst -- The object in which an attribute is found

      name -- The attribute name

      v -- The attribute value

      extra -- The 'extra' value passed to 'acquire' or None.

    The filter function should return 1 if the attribute should
    be returned by acquire and 0 otherwise.  It may also raise an
    error, in which case the error is propigated.