- update to 1.5.2
* support for cffi-based embedding
* more robustness for shutdown logic

- update to version 1.4.2:
* Nothing changed from v1.4.1.
- changes from version 1.4.1:
* Fix the compilation failure of cffi on CPython 3.5.0. (3.5.1
works; some detail changed that makes some underscore-starting
macros disappear from view of extension modules, and I worked
around it, thinking it changed in all 3.5 versions—but no: it was
only in 3.5.1.)
- changes from version 1.4.0:
* A better way to do callbacks has been added (faster and more
portable, and usually cleaner). It is a mechanism for the
out-of-line API mode that replaces the dynamic creation of
callback objects (i.e. C functions that invoke Python) with the
static declaration in cdef() of which callbacks are needed. This
is more C-like, in that you have to structure your code around the
idea that you get a fixed number of function pointers, instead of
creating them on-the-fly.
* ffi.compile() now takes an optional verbose argument. When True,
distutils prints the calls to the compiler.
* ffi.compile() used to fail if given sources with a path that
includes "..". Fixed.
* ffi.init_once() added. See docs.
* dir(lib) now works on libs returned by ffi.dlopen() too.
* Cleaned up and modernized the content of the demo subdirectory in
the sources (thanks matti!).
* ffi.new_handle() is now guaranteed to return unique void * values,