From: Evgenii Philippov <efilippov@gmail.com>
From: Evgenii Philippov <efilippov@gmail.com>

Relex code depends on SentenceDetector returning nulls when 
there are no sentences.  Otherwise it goes into infinite loops.

Signed-off-by: Evgenii Philippov
Signed-off-by: Linas Vepstas

AmeBel/relex,rodsol/relex-temp,rodsol/relex-temp,williampma/relex,williampma/relex,ainishdave/relex,anitzkin/relex,anitzkin/relex,rodsol/relex,williampma/relex,leungmanhin/relex,anitzkin/relex,ainishdave/relex,opencog/relex,opencog/relex,williampma/relex,ainishdave/relex,rodsol/relex-temp,linas/relex,rodsol/relex-temp,rodsol/relex,opencog/relex,anitzkin/relex,rodsol/relex-temp,virneo/relex,virneo/relex,linas/relex,rodsol/relex,leungmanhin/relex,AmeBel/relex,AmeBel/relex,virneo/relex,linas/relex,anitzkin/relex,rodsol/relex,virneo/relex,ainishdave/relex,leungmanhin/relex