Added the docs for the compiler options. Used autodata to avoid duplication of the options descriptions in the docs and in the python file.

Made code examples in the docs compatible with python 2 and 3.

See #2279.

Fixing c library tutorial

Added a C++ example in the cython tutorial.

Make non-standard Extension attributes "py_limited_api" and "np_pythran" optional for cycache fingerprinting.

Added a documentation for the Cythonize function and its arguments.

Fixed the formatting of a note in special_methods.rst.

Replaced the text in reference/extension_types.rst by links to the corresponding sections in the userguide.

Transfer of the dynamic attributes into the userguide.

Replaced the text in reference/extension_types.rst by links to the corresponding sections in the userguide.

Transfered a note from the reference guide extension types to the userguide.

Also reject conflicting duplicates of top-level directives.
Closes #2230.

Support more C file extensions when searching modules during coverage analysis: .cc and .cxx in addition to the current .c and .cpp.
Closes #2266.

Avoid segfault due to a bug in g++ 4.4.7 when the -Os setting for the module init function is enabled.
Closes #2235.