Pyhdf

* setup.py: detect libhdf-alt-dev on Debian-based systems (Fixes 11)
* setup.py: handle additional linker arguments correctly (19)
* Regenerate C extension with newer version of swig
* SD: remove outdated SWIG workaround for negative INT8 (Fixes 15)

* SD: added support for long variable names (1ad85ef17a194b62bbe5c6c3eeda12b55b6666ae)

Here are the major changes in this release:
- Add support for Python 3
- VS: fixes python 2.7 compatibility (c1655f6a18)
- VS: fixes buffer overflow when reading long VData field names (c1655f6a18)
- SD: remove warning about use of deprecated Numpy API (e4ab8e3543)
- SD: fixes buffer overflow for long dataset name (1, 7a3420a369)
- NOSZIP environment variable used during installation has been changed to SZIP (c91dd79afb)
- Easier installation in common Linux distributions (c91dd79afb)
- Most of the documentation has been formatted for Sphinx