Naive approach to fix memview incref/decref asymmetry in transpose

This patch contains test-case along with a blind patch that fixes the test (but
may have other consequences, someone who actually understands the code must
review it).

Original error was:
Fatal Python error: Acquisition count is 0 (line XYZ)

which was caused by refcount error when memview transposition was used on
extension class memoryview attribute.
Add casting to const

The included test is derived from a real world case
which would lead to warnings in GCC if the pointer
wouldn't be explicitly casted to const.
changelog
fix C++ warning
add "experimental!" warning to linetrace directive
Const cast fix.
Merge pull request #204 from vmx/constcast

Add casting to const
Undo redundant fix.
Ensure NAN is always initialized.
changelog
explain difference between cdef and cpdef
explain difference between cdef and cpdef
explain difference between cdef and cpdef
explain difference between cdef and cpdef
explain difference between cdef and cpdef
Merge pull request #210 from nbruin/master

Explain difference between cdef and cpdef
Fix build for non-C99 compatible compilers
Merge pull request #211 from Juntalis/master

Non-Wrapped Inline Declaration Breaking Compatibility with C89 Compilers
update docs on optimised builtins

--HG--
extra : rebase_source : fb47cc7e0154abb172016f1945dad2968b3f2a3e
inline normal case of getattr(o,n)

--HG--
extra : rebase_source : 9a5bbb4f08a0eb5be71afd48d9ad5566d8a39efc