pinned down error code enum values

Note : all error codes are changed by this new version,
but it's expected to be the last change for existing codes.

Codes are now grouped by category, and receive a manually attributed value.
The objective is to guarantee that
error code values will not change in the future
when introducing new codes.
Intentionnal empty spaces and ranges are defined
in order to keep room for potential new codes.

lib/dictBuilder/zdict.c

@@ -695,7 +695,7 @@ static size_t ZDICT_analyzeEntropy(void*  dstBuffer, size_t maxDstSize,
         DISPLAYLEVEL(1, "Not enough memory \n");
         goto _cleanup;
     }
-    if (offcodeMax>OFFCODE_MAX) { eSize = ERROR(dictionary_wrong); goto _cleanup; }   /* too large dictionary */
+    if (offcodeMax>OFFCODE_MAX) { eSize = ERROR(dictionaryCreation_failed); goto _cleanup; }   /* too large dictionary */
     for (u=0; u<256; u++) countLit[u] = 1;   /* any character must be described */
     for (u=0; u<=offcodeMax; u++) offcodeCount[u] = 1;
     for (u=0; u<=MaxML; u++) matchLengthCount[u] = 1;