New helper function.

Added a new helper function converting a vector of unit length given in
dip and azimuth to a unit vector in the vertical, south, east coordinate
system.
Added arbitrary dip/azimuth rotation.

Added a new function that allows to specify the orientation of each
component seperately with dip and azimuth. The components do not have to
be orthogonal to each other it should work nonetheless. The output are
three new arrays, always oriented Up, North, East
Added rotate2ZNE method to obspy.xseed.parser.Parser

This enable the (very basic) fully automatic rotation of arbitrarily
oriented components to ZNE. Also renames the channels.
Added test for the Parser rotation method.
Added test files.
Updating changelog
Better docstrings.
Merge branch 'master' into rotations.

Resolved conflicting CHANGELOG.
decorator to add processing information to trace in a more general and
standardized way
use new decorator to add trace processing info
add @kaeufl to credits, see #724
fdsn: add neries/seismicportal url mapping
avoiding future dependency in setup.py

problem was imported obspy.core.version.

Probably we can get rid of most from future.builtins import open
lines...

see #730
Trying to resolve sphinx build failures

seems like for older versions of numpy mode must not be unicode, forcing
native string.

Failure were:
* http://tests.obspy.org/12773/#15
* http://tests.obspy.org/12773/#16
fixing some doctests in fsdn.client

* http://tests.obspy.org/12773/#9
* http://tests.obspy.org/12773/#10
Merge branch 'releases' of https://github.com/obspy/obspy
Test case for issue with global state in obspy.taup.
clear message if numpy is missing at install time. closes #730
Merge remote-tracking branch 'upstream/releases'
Correcting docs (based on sphinx output)

see #725 and http://docs.obspy.org/master/log.txt