Two new FDSN tests.

Tests the created URLS. Fixing some minor bugs along the
way.
Adjusting test cases once again...
Custom per-service endpoints can now be specified.

Also added a short test.
changelog
fdsn: add possibility to deactivate single services in client (+test)
Added test for actually downloading things with custom mappings.
PEP8
fdsn tests: only initialize clients once
Merge pull request #754 from krischer/fdsn_enhancements

Feature request: override capabilty for specific FDSN web service locations
scale down docstring example plot in tf_misfit.py

@martinvandriel, this example plot in the docs consumed 2.5 GB of
memory, making sphinx docs building fail erratically for me (and running
my RAM full several times in the process). Even with these reduced
settings it takes 300 MB, maybe there is something wrong in there?
..this memory consumption seems a bit excessive.
some sphinx doc building fixes

- short timeouts for all earthworm requests (test server down)
- update citations
add util funtion to cleanse a filename for a python module
use conforming names for library names
avoid dangerous code duplication runtime/build time

comes at the cost of making sure to have no "from obspy .." imports in
the files used at installation time (currently version.py and misc.py in
core.util)
add a basic test to check files used at install time for obspy imports
runtests: add option to only keep images of failed image tests

the imgur upload script seems to get rejected after too many uploads,
and in most cases only the failed images are of interest.
travis: fix matplotlib version to 1.3.1
fix cygwin support for mseed

will be fixed upstream in libmseed for future updates of libmseed, but
this will fix cygwin installation in the meantime until we pull in a
libmseed update.
removed the try-except - added logger.error(str(e))

Conflicts:
	obspy/seedlink/client/seedlinkconnection.py
update credits