Cleanup of imports in _features.pyx.  Switched band IO to use _io.io_ubyte instead of duplicate in _featuers.pyx
Updated test_update to deal with platform specific line endings causing test to fail.  Migrated test_write to py.test and updated to relax precision required for pixel size in gdalinfo (varies in trivial manner across platforms causing tests to fail).
Merge remote-tracking branch 'Upstream/master'
Merge pull request #65 from brendan-ward/master

Cleanup of failing tests on windows and imports in _features.pyx