Small cleanup of QCBOR_DISABLE_EXP_AND_MANTISSA, remove QCBOR_DISABLE_UNCOMMON_TAGS

Expand test coverage for decimal fractions. Fix c++ for qcbor_decode_tags.h. Close out some tag-related TODO's that didn't need much. Tidy up  QCBOR_DISABLE_EXP_AND_MANTISSA #ifdefs


* Small cleanup of QCBOR_DISABLE_EXP_AND_MANTISSA

* Remove DISABLE_UNCOMMON_TAGS

* expand decimal frac test coverage; close out todo's

---------

Co-authored-by: Laurence Lundblade <lgl@securitytheory.com>
diff --git a/src/qcbor_decode.c b/src/qcbor_decode.c
index 2992ce1..73ae425 100644
--- a/src/qcbor_decode.c
+++ b/src/qcbor_decode.c
@@ -5637,7 +5637,7 @@
    return (*pfExp)(uMantissa, nExponent, puResult);
 }
 
-#endif /* QCBOR_DISABLE_EXP_AND_MANTISSA */
+#endif /* ! QCBOR_DISABLE_EXP_AND_MANTISSA */
 
 
 
@@ -6060,7 +6060,7 @@
             return QCBOR_ERR_UNEXPECTED_TYPE;
          }
          break;
-#endif /* QCBOR_DISABLE_EXP_AND_MANTISSA */
+#endif /* ! QCBOR_DISABLE_EXP_AND_MANTISSA */
 
 
       default:
@@ -6459,7 +6459,7 @@
             return QCBOR_ERR_UNEXPECTED_TYPE;
          }
          break;
-#endif /* QCBOR_DISABLE_EXP_AND_MANTISSA */
+#endif /* ! QCBOR_DISABLE_EXP_AND_MANTISSA */
       default:
          return QCBOR_ERR_UNEXPECTED_TYPE;
    }
diff --git a/src/qcbor_tag_decode.c b/src/qcbor_tag_decode.c
index 36e8dae..33e8dba 100644
--- a/src/qcbor_tag_decode.c
+++ b/src/qcbor_tag_decode.c
@@ -182,7 +182,7 @@
          return uBase;
 
       case QCBOR_TYPE_UINT64:
-         return uBase + (QCBOR_TYPE_DECIMAL_FRACTION_POS_U64 - QCBOR_TYPE_DECIMAL_FRACTION); // TODO: test this
+         return uBase + (QCBOR_TYPE_DECIMAL_FRACTION_POS_U64 - QCBOR_TYPE_DECIMAL_FRACTION);
 
       case QCBOR_TYPE_65BIT_NEG_INT:
          return uBase + (QCBOR_TYPE_DECIMAL_FRACTION_NEG_U64 - QCBOR_TYPE_DECIMAL_FRACTION);
@@ -268,7 +268,7 @@
               MantissaItem.uDataType == QCBOR_TYPE_NEGBIGNUM) {
       /* Got a good big num mantissa */
       pDecodedItem->val.expAndMantissa.Mantissa.bigNum = MantissaItem.val.bigNum;
-#endif /* QCBOR_DISABLE_TAGS */
+#endif /* ! QCBOR_DISABLE_TAGS */
    } else if(MantissaItem.uDataType == QCBOR_TYPE_UINT64) {
       pDecodedItem->val.expAndMantissa.Mantissa.uInt = MantissaItem.val.uint64;
    } else if(MantissaItem.uDataType == QCBOR_TYPE_65BIT_NEG_INT) {
@@ -346,7 +346,7 @@
    {CBOR_TAG_B64,           QCBOR_TYPE_BASE64},
    {CBOR_TAG_REGEX,         QCBOR_TYPE_REGEX},
    {CBOR_TAG_BIN_UUID,      QCBOR_TYPE_UUID                  | IS_BYTE_STRING_BIT},
-   {CBOR_TAG_CBOR_SEQUENCE, QBCOR_TYPE_WRAPPED_CBOR_SEQUENCE | IS_BYTE_STRING_BIT}, // TODO: does this belong here?
+   {CBOR_TAG_CBOR_SEQUENCE, QBCOR_TYPE_WRAPPED_CBOR_SEQUENCE | IS_BYTE_STRING_BIT},
    {CBOR_TAG_INVALID16,     QCBOR_TYPE_NONE}
 };
 
@@ -408,17 +408,15 @@
    {CBOR_TAG_B64,              QCBORDecode_StringsTagCB},
    {CBOR_TAG_REGEX,            QCBORDecode_StringsTagCB},
    {CBOR_TAG_BIN_UUID,         QCBORDecode_StringsTagCB},
-   {CBOR_TAG_CBOR_SEQUENCE,    QCBORDecode_StringsTagCB}, // TODO: does this belong here?
+   {CBOR_TAG_CBOR_SEQUENCE,    QCBORDecode_StringsTagCB},
    {CBOR_TAG_MIME,             QCBORDecode_MIMETagCB},
    {CBOR_TAG_BINARY_MIME,      QCBORDecode_MIMETagCB},
 #ifndef QCBOR_DISABLE_EXP_AND_MANTISSA
-
    {CBOR_TAG_BIGFLOAT,         QCBORDecode_ExpMantissaTagCB},
    {CBOR_TAG_DECIMAL_FRACTION, QCBORDecode_ExpMantissaTagCB},
-#endif
+#endif /* ! QCBOR_DISABLE_EXP_AND_MANTISSA */
    {CBOR_TAG_DAYS_EPOCH,       QCBORDecode_DaysEpochTagCB},
    {CBOR_TAG_INVALID64,        NULL},
 };
 
 #endif /* ! QCBOR_DISABLE_TAGS */
-