Fix threading test that sporadically fails on Travis.

threading.active_count will return the number of threads that would be
returned by threading.enumerate. These may include additional worker
threads that are unrelated to the user-spawned threads, and would cause
the loop to continue to wait even though all user-spawned threads were
totally complete.
add missing symbol curr_file to .def file
More resilient StationXML parser.

It now pops a warning when it cannot convert some string to a float or
the float is a NaN. It does not stop parsing anymore. This is
unfortunately needed for some real data out there.
Don't install suds-jurko on Travis.

It doesn't appear that the NERIES client is tested on Travis, so this
import is not needed.
Pin NumPy and SciPy to versions in the wheelhouse.

Matplotlib 1.3.1 and NumPy 1.9.0 are incompatible (so it surprises me
that they'll both install), and cause test failures.
Don't install M2Crypto on Travis.

It's used by Arclink, but not tested.
Add M2Crypto to EXTRA_REQUIRES.

Not sure why it hasn't been mentioned before.
Remove extra parentheses in print function calls.
Bump NumPy version to match wheelhouse.
Merge pull request #884 from QuLogic/doc-linkcheck

Update doc links
Deprecate matplotlib.mlab.psd wrapper.

Its purpose was to make results similar for matplotlib < 0.99.4, but we
require matplotlib 1.0.0 now.
Remove old matplotlib calls in imaging.spectrogram.
Remove matplotlib 0.91.2 compatibility code.