- internal inverse index reworked

the testrunner.

to provide some minor speedup. But this made it impossible to
store unicode strings. So we can now store unicode strings
in a Lexicon *yippi*

Add getLogFile() method that provides hook for SpreadLog subclass.

- better debug messages

(quotation+colon+URL or quotation+comma+whitespace+URL) did not
work properly (thanks to Alastair Burt for reporting and submitting
the patch).