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.
Add ZMAP write support for earthquake catalogs
Improve python 3 compatibility

...by explicitly encoding/decoding strings when writing/reading to files.
Fix minor issues
Open files in context, minor improvements
Minor improvements
Add ZMAP read support
Remove unused doctests
Move ZMAP support do dedicated package
Fix python 2.6 compatibility
Another python 2.6 compatibility fix
Rename zmap module to core, fix doctests
Fix python 3.3 compatibility issue
Added obspy.zmap to doc overview page.
Some restructuring of the zmap documentation.

Fixed some RST issues and reordered it a bit. Also included the
licensing information.