+ /*
+ // Usage example
+ const char *key, *val;
+ void *iter = sam_header_parse2(bam->header->text);
+ while ( iter = sam_header_key_val(iter, "RG","ID","SM" &key,&val) ) printf("%s\t%s\n", key,val);
+ */
+ void *sam_header2key_val(void *iter, const char type[2], const char key_tag[2], const char value_tag[2], const char **key, const char **value);