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

fmt_ldapsearchfilter.c

@@ -1,5 +1,4 @@
 #include <byte.h>
-#include "asn1.h"
 #include "ldap.h"
 #include <stdlib.h>
 
@@ -51,7 +50,7 @@ size_t fmt_ldapsearchfilter(char* dest,struct Filter* f) {
     }
     break;
   case PRESENT:
-    return fmt_asn1string(dest,PRIVATE,PRIMITIVE,f->type,f->ava.desc.s,f->ava.desc.l);
+    return fmt_asn1string(dest,PRIVATE,PRIMITIVE,(enum asn1_tag)f->type,f->ava.desc.s,f->ava.desc.l);
     break;
   default: return 0;
   }