some tests are expected to fail (for now).

--HG--
branch : pure-cffi
more specific errors for bad FFMpeg libraries.

--HG--
branch : pure-cffi
full coverage for the versions module.

--HG--
branch : pure-cffi
rename for (better?) clarity

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branch : pure-cffi
rename : tests/test_common.py => tests/test_formats.py
more tests

--HG--
branch : pure-cffi
iosource tests stubs.

--HG--
branch : pure-cffi
reboot the demuxer tests.

--HG--
branch : pure-cffi
renamed for consistency with project best practices.

--HG--
branch : pure-cffi
rename : COPYING => LICENSE
rename : doc/pyrana-API.py => docs/pyrana-API.py
add requirements.txt and list dependencies in setup.py

--HG--
branch : pure-cffi
Merge ../pyrana