add "generic" format string based encoder and decoder (scan_asn1generic,

fmt_asn1generic, see t10.c for example usage)
add "generic" asn.1 dumper (in t10.c)
fix some read off-by-one errors, minor cleanups
add real OID support
add bitstring support

scan_ldapsearchfilter.c

@@ -1,4 +1,3 @@
-#include "asn1.h"
 #include "ldap.h"
 #include <stdlib.h>
 
@@ -40,7 +39,7 @@ size_t scan_ldapsearchfilter(const char* src,const char* max,struct Filter** f)
   if (tc!=PRIVATE || (tt!=CONSTRUCTED && tag!=7) || tag>9) goto error;
   if (!(tmp=scan_asn1length(src+res,max,&len))) goto error;
   res+=tmp;
-  if (src+res+len>max) goto error;
+  if (src+res+len>=max) goto error;
   if (!(*f=malloc(sizeof(struct Filter)))) goto error;
   (*f)->next=0;
   (*f)->x=0;