Merge pull request #10 from pyca/python3-porting-fixes

Correct some mistakes made during earlier Python 3 porting work.  Mainly, keep accepting both bytes and unicode in a few APIs.
support 64 bit fd's
use six's integer_types instead of py3 incompatible type 'long'
add .gitignore
allow tests to run even without execinfo.h
make test_closed pass on windows
Merge pull request #25 from longaccess/fix_test_closed

Use `getwinerror` to look up a syscall error code on Windows.  Fixes `test_closed` on Windows.
Merge pull request #20 from kouk/longint

Add support for file descriptors represented as `long` on Python 2.x.  This fixes many failing tests on 64 bit Windows w/ 64 bit Python.

Also some other changes to make `memdbg` optional (it is pretty glibc-specific).
Merge pull request #21 from kouk/gitignore

Add a .gitignore to ignore a few common build artifacts.
Change the info callback test to at least assert that the connection argument is a Connection instance.

Fix the implementation to make the test pass.
clean up messy comment
Merge pull request #26 from pyca/info-callback-argument

Pass a Connection instance to the info callback (instead of a Context instance).  Fixes #16 (a regression introduced by the Python rewrite).
cffi callbacks are easy
There is a top-level INSTALL document now.  Let's not be redundant.
github!  python.org!
Merge pull request #27 from pyca/misc-documentation-fixes

Get rid of obsolete implementation notes and installation instructions.  Introduce links to the websites relevant to the project into the README.
Add some missing test coverage for handling values of type `long` and fix the implementation to accept either `int` or `long` on Python 2 (more closely matching the API implemented by the old C code).
tests and fixes for other int/long cases
Merge commit '541150d' into release-0.14 (Fix `test_closed` on Windows)
Merge commit '410d042' into release-0.14 (Fix many tests on 64 bit Python on Windows)