__init__, hazard/parsers:

Added `iterparse_tree` util function to reduce some code duplication.
hazard/parsers:

Renamed HazardCurveParser HazardCurveXMLParser and added a
HazardCurveParser wrapper function to display a deprecation warning
if it is used.
models:

Refactored the behavior of HazardCurveModel. The interface is pretty
much the same, but do this change makes it easier and more intuitive
to access metadata (via the `metadata` attribute).
hazard/writers:

Renamed BaseCurveXMLWriter to BaseCurveWriter. This base functionality
can be extended to other formats as well.
tests/hazard/parsers_test:

Refactored HazardCurveParserTestCase a bit to match some changes in the
models. The general test strategy has not changed.
hazard/writers:

Added `HazardCurveGeoJSONWriter`.
tests/hazard/writers_test:

Added tests for `HazardCurveGeoJSONWriter`.
hazard/writer:

Trivial refactoring to make code more readable in
`HazardMapGeoJSONWriter`.
examples:

Added some hazard curve geojson examples to match the ones already
existing in XML format.
hazard/parsers:

Implemented HazardCurveGeoJSONParser.
tests/hazard/parsers_test:

Changed a class reference to remove a deprecation warning.
tests/hazard/parsers_test:

Add tests for HazardCurveGeoJSONParser.
hazard/writers:

Added pretty printing for hazard curve and map json output.
risk/writers:

Added pretty print to LossMapGeoJSONWriter.
Merge branch 'hc-geojson' of https://github.com/larsbutler/oq-nrmllib
Fixed a merge conflict
Fixed the StreamingXMLWriter broken in Python 2.7.5
Changed assert_xml_equal to not depend on lxml
Merge pull request #111 from gem/streaming-xml-writer

Fixed the streaming xml writer