asian language support for the indexer #563

Asian languages do not use spaces to seperate words. The indexer however does
a word based lookup. Splitting for example Japanese texts into real words is
only possible with complicated natural language processing, something
completely out of scope for DokuWiki.

This patch solves the problem by treating all asian characters as single
words. When an asian word (consisting of multiple characters) is searched it
is treated as a phrase search, looking up each charcter by it self first,
then checking for the phrase in found documents.

darcs-hash:20050925175451-7ad00-933b33b51b5f2fa05e736c18b8db58a5fdbf41ce.gz