RUBY-2861 update documentation to drop BSON:: (#278)

Author: neilshweky

docs/tutorials/bson-v4.txt

@@ -528,29 +528,29 @@ BSON::Decimal128 vs BigDecimal
 The ``BigDecimal`` ``from_bson`` and ``to_bson`` methods use the same
 ``BSON::Decimal128`` methods under the hood. This leads to some limitations
 that are imposed on the ``BigDecimal`` values that can be serialized to BSON
-and those that can be deserialized from existing ``BSON::Decimal128`` BSON
-objects. This change was made because serializing ``BigDecimal`` instances as
+and those that can be deserialized from existing ``decimal128`` BSON
+values. This change was made because serializing ``BigDecimal`` instances as
 ``BSON::Decimal128`` instances allows for more flexibility in terms of querying
 and aggregation in MongoDB. The limitations imposed on ``BigDecimal`` are as
 follows:
 
-- ``BSON::Decimal128`` has a limited range and precision, while ``BigDecimal``
-  has no restrictions in terms of range and precision. ``BSON::Decimal128`` has
-  a max value of approximately ``10^6145`` and a min value of approximately
-  ``-10^6145``, and has a maximum of 34 bits of precision.
+- ``decimal128`` has a limited range and precision, while ``BigDecimal`` has no
+  restrictions in terms of range and precision. ``decimal128`` has a max value
+  of approximately ``10^6145`` and a min value of approximately ``-10^6145``,
+  and has a maximum of 34 bits of precision.
 
-- ``BSON::Decimal128`` is able to accept signed ``NaN`` values, while
-  ``BigDecimal`` is not. All signed ``NaN`` values that are deserialized into
-  ``BigDecimal`` instances will be unsigned.
+- ``decimal128`` is able to accept signed ``NaN`` values, while ``BigDecimal``
+  is not. All signed ``NaN`` values that are deserialized into ``BigDecimal``
+  instances will be unsigned.
 
-- ``BSON::Decimal128`` maintains trailing zeroes when serializing to and
+- ``decimal128`` maintains trailing zeroes when serializing to and
   deserializing from BSON. ``BigDecimal``, however, does not maintain trailing
   zeroes and therefore using ``BigDecimal`` may result in a lack of precision.
 
 .. note::
 
-  In BSON 5.0, ``BSON::Decimal128`` is deserialized into ``BigDecimal`` by
-  default. In order to have ``BSON::Decimal128`` values in BSON documents
+  In BSON 5.0, ``decimal128`` will be deserialized into ``BigDecimal`` by
+  default. In order to have ``decimal128`` values in BSON documents
   deserialized into ``BSON::Decimal128``, the ``mode: :bson`` option can be set
   on ``from_bson``.