minor fixes in related work section

src/tutorial/related_work.rst

 Related work
 ============
 
-Pyrex [Pyrex]_ is the compiler project that Cython was originally based on.
-Many features and the major design decisions of the Cython language
-were developed by Greg Ewing as part of that project.  Today, Cython
-supersedes the capabilities of Pyrex by providing a higher
-compatibility with Python code and Python semantics, as well as
-superior optimisations and better integration with scientific Python
-extensions like NumPy.
+Pyrex [Pyrex]_ is the compiler project that Cython was originally
+based on.  Many features and the major design decisions of the Cython
+language were developed by Greg Ewing as part of that project.  Today,
+Cython supersedes the capabilities of Pyrex by providing a
+substantially higher compatibility with Python code and Python
+semantics, as well as superior optimisations and better integration
+with scientific Python extensions like NumPy.
 
 ctypes [ctypes]_ is a foreign function interface (FFI) for Python.  It
 provides C compatible data types, and allows calling functions in DLLs
@@ -20,23 +20,24 @@ operations must pass through Python code first.  Cython, being a
 compiled language, can avoid much of this overhead by moving more
 functionality and long-running loops into fast C code.
 
-SWIG [SWIG]_ is a wrapper code generator.  It makes it very easy to parse
-large API definitions in C/C++ header files, and to generate straight
-forward wrapper code for a large set of programming languages.  As
-opposed to Cython, however, it is not a programming language itself.
-Thin wrappers are easy to generate, but the more functionality a
-wrapper needs to provide, the harder it gets to implement it with
-SWIG.  Cython, on the other hand, makes it very easy to write very
-elaborate wrapper code specifically for the Python language.  Also,
-there exists third party code for parsing C header files and using it
-to generate Cython definitions and module skeletons.
+SWIG [SWIG]_ is a wrapper code generator.  It makes it very easy to
+parse large API definitions in C/C++ header files, and to generate
+straight forward wrapper code for a large set of programming
+languages.  As opposed to Cython, however, it is not a programming
+language itself.  Thin wrappers are easy to generate, but the more
+functionality a wrapper needs to provide, the harder it gets to
+implement it with SWIG.  Cython, on the other hand, makes it very easy
+to write very elaborate wrapper code specifically for the Python
+language, and to make it as thin or thick as needed at any given
+place.  Also, there exists third party code for parsing C header files
+and using it to generate Cython definitions and module skeletons.
 
 ShedSkin [ShedSkin]_ is an experimental Python-to-C++ compiler. It
-uses profiling information and very powerful type inference engine
-to generate a C++ program from (restricted) Python source code. 
-The main drawback is has no support for calling the Python/C API for
-operations it does not support natively, and supports very few of the
-standard Python modules.
+uses a very powerful whole-module type inference engine to generate a
+C++ program from (restricted) Python source code.  The main drawback
+is that it has no support for calling the Python/C API for operations
+it does not support natively, and supports very few of the standard
+Python modules.
 
 .. [ctypes] http://docs.python.org/library/ctypes.html.
 .. there's also the original ctypes home page: http://python.net/crew/theller/ctypes/