removed all not null from identityxrefs, will allow easy filliung from old...

removed all not null from identityxrefs, will allow easy filliung from old data, all additional fields for alignments, scores anmd analysis are optional

sql/table.sql

@@ -548,11 +548,11 @@ CREATE TABLE identity_xref(
 	hit_end int,
 	translation_start int,
 	translation_end int,
-	cigar_line text not null,
+	cigar_line text,
 	
 	score double,
 	evalue double,
-	analysis_id int not null,
+	analysis_id int,
 
         PRIMARY KEY (object_xref_id)
 );