some changes for quakeml transition
quakeml: adapting xpath expressions
refactor custom namespace
adapting index names for quakeml
Merge remote-tracking branch 'upstream/master' into HEAD
switching QuakeML validation to RelaxNG

- official schema files were merged. otherwise seishub is not able to
  resolve the include from the second schema file in the umbrella schema
  at run time
- minor fix for official file, see
  http://intensity.usc.edu/pipermail/quakeml/2013-April/000146.html
adding relaxng files to MANIFEST
Merge remote-tracking branch 'upstream/master' into quakeml
Merge remote-tracking branch 'upstream/master' into quakeml
add indexes for P/S phase count custom namespace fields
quakeml: style sheet to convert seiscomp xml into proper quakeml
transition stylesheets to quakeml
migrate indexing to quakeml

mostly takes care of "preferredXXX" handling for origin, magnitude and
focalMechanism:
- any "preferred" item is used for indexing, if one is specified in the
  corresponding event-subtag (e.g. preferredOrigin)
- if the "preferred" subtag is missing, any first item is used for
  indexing (e.g. first origin in xml file)
Merge pull request #3 from megies/quakeml

Official Quakeml based events