Updates Changes.md

Changes.md

@@ -18,8 +18,8 @@ as API (Application Programming Interface) changes, Testbed changes, and other c
   All shapes can collide with any other shape now (chains can collide with other
   chains or edges or any other kind of shape).
 - All shapes support vertex-radius based corner rounding now. This enables
-  [*capsule shapes* and other visibly rounded shapes](https://github.com/louis-langholtz/PlayRho/blob/master/Documentation/images/RoundedCornerShapes.png).
-- [Rounded and modified corner collisions](https://github.com/louis-langholtz/PlayRho/blob/master/Documentation/CollisionHandlng.md).
+  [*capsule shapes* and other visibly rounded shapes](Documentation/images/RoundedCornerShapes.png).
+- [Rounded and modified corner collisions](Documentation/CollisionHandlng.md).
   This supports the physical behaviors expected of rounded corners, like
   increased roll-ability, while preventing dragged shapes from getting stuck
   on composite surfaces.
@@ -32,19 +32,19 @@ as API (Application Programming Interface) changes, Testbed changes, and other c
   them (from Fixture class) for reduced memory usage.
 - Renamed circle shapes as "disk" shapes to distinguish them as solid and never hollow.
 - Switched from reference-semantics to value-semantics. Pointers are gone from the interface. References to bodies, fixtures, joints, and contacts have been replaced with identifiers and function interfaces.
-- Converted public "virtual" interfaces to value-semantic polymorphic value types.
+- Converted public "virtual" interfaces to value-semantic polymorphic value types. For an introduction to polymorphic value types, please check out [C++: My Love Affair With Polymorphic Value Types](https://gist.github.com/louis-langholtz/5da900c8333eed26641a09bea7aa5c31).
 - Added support for C++11 range-based loops and constant expressions.
 - Added compile-time support for "zero-runtime-overhead" strongly-typed physical units (using an
   interface to [`constexpr` enhanced boost units](https://github.com/louis-langholtz/units)).
   For details on how to enable this, see
-  [Documentation/PhysicalUnits.md](https://github.com/louis-langholtz/PlayRho/blob/master/Documentation/PhysicalUnits.md).
+  [Documentation/PhysicalUnits.md](Documentation/PhysicalUnits.md).
 - Added compile-time support for `double` and `long double` floating-point types (in addition to `float`), and 32-bit and 64-bit fixed-point types.
 - Fully per-step run-time configurable (via
-  [`StepConf`](https://github.com/louis-langholtz/PlayRho/blob/master/PlayRho/Dynamics/StepConf.hpp)).
+  [`StepConf`](PlayRho/Dynamics/StepConf.hpp)).
 - In-depth per-step return value statistics (via
-  [`StepStats`](https://github.com/louis-langholtz/PlayRho/blob/master/PlayRho/Dynamics/StepStats.hpp)).
+  [`StepStats`](PlayRho/Dynamics/StepStats.hpp)).
 - Increased construction-time configurability of world instances (via
-  [`World::Def`](https://github.com/louis-langholtz/PlayRho/blob/master/PlayRho/Dynamics/World.hpp#L107)).
+  [`WorldConf`](PlayRho/Dynamics/WorldConf.hpp)).
 - Refactored numerous methods to be
   [non-member non-friend functions](http://www.drdobbs.com/cpp/how-non-member-functions-improve-encapsu/184401197).
 - Refactored various functions and procedures to be
@@ -58,7 +58,7 @@ as API (Application Programming Interface) changes, Testbed changes, and other c
 
 ## Testbed changes
 
-- Updated UI to provide full access to the per-step configurability, per-step statistics.
+- Updated UI to provide full access to the per-step configurability and per-step statistics.
 - Added the ability to manipulate bodies while paused.
 - Added additional paths to find font and a font-less mode (instead of aborting).
 - Added more demonstrations/tests: Half Pipe, iforce2d's Topdown Car, Orbiter, Newton's
@@ -68,7 +68,7 @@ as API (Application Programming Interface) changes, Testbed changes, and other c
 ## Other Changes
 
 - Unit tested via [Google Test](https://github.com/google/googletest/tree/aa148eb2b7f70ede0eb10de34b6254826bfb34f4)
-  and [over 400 tests](https://github.com/louis-langholtz/PlayRho/tree/master/UnitTests).
+  and [over 1000 tests](UnitTests).
 - Added continuous integration (CI) building and unit testing of repository updates
   for the Linux and Windows platforms.
 - Configured use of [COVERALLS](https://coveralls.io/github/louis-langholtz/PlayRho?branch=dev)