Squeeze nested structure arrays.

[u55]

Fixes #2.

[u55]

Note, this works correctly (it seems) for my use case, but I have not figured out how to run the matloader test suite.

[anntzer]

nosetests doesn't work?

[u55]

Ok, I got nosetests to work. There are two failures, but they are unrelated to anything I did, and they also fail with the current master on my machine. Tested on Arch Linux, python 3.6.

$ nosetests
....................................................................................................................................................................................................................................EE
======================================================================
ERROR: Failure: ValueError (seek of closed file)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/nose/failure.py", line 39, in runTest
    raise self.exc_val.with_traceback(self.tb)
  File "/usr/lib/python3.6/site-packages/nose/loader.py", line 251, in generate
    for test in g():
  File "/home/sbs/sources/customized/python-matloader-git/src/matloader/tests/test_streams.py", line 66, in test_tell_seek
    res = st.seek(0)
  File "matloader/streams.pyx", line 54, in matloader.streams.GenericStream.seek (matloader/streams.c:2497)
  File "matloader/streams.pyx", line 55, in matloader.streams.GenericStream.seek (matloader/streams.c:2382)
ValueError: seek of closed file

======================================================================
ERROR: Failure: ValueError (seek of closed file)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/nose/failure.py", line 39, in runTest
    raise self.exc_val.with_traceback(self.tb)
  File "/usr/lib/python3.6/site-packages/nose/loader.py", line 251, in generate
    for test in g():
  File "/home/sbs/sources/customized/python-matloader-git/src/matloader/tests/test_streams.py", line 83, in test_read
    st.seek(0)
  File "matloader/streams.pyx", line 54, in matloader.streams.GenericStream.seek (matloader/streams.c:2497)
  File "matloader/streams.pyx", line 55, in matloader.streams.GenericStream.seek (matloader/streams.c:2382)
ValueError: seek of closed file

----------------------------------------------------------------------
Ran 230 tests in 0.499s

FAILED (errors=2)