* fix ucs4 build broken by bb13ec
* add utf16 decoding to unicode.from_py_object for
narrow unicode builds
* change unicode narrow/wide cfg flag to be
Py_UNICODE_SIZE_4 not Py_UNICODE_WIDE, which doesn't
appear in sysconfig
* support framework builds on os x
* python27-sys exports compilation flags as cargo vars,
and rust-python resurrects them as cfg flags
* travis runs against local python27-sys
* rust-cpython depends on git python27-sys, because
the one on cargo is now incompatible with it (since bb13ec)
* in build.rs, call the python interpreter located by pkgconfig
and use sysconfig to determine the flags it was built with.
* pass these flags to the build via --cfg
* refactor existing references to features to refer to these
instead
Daniel Grunwald