Incomplete - task : implement pyMongo repository
Incomplete - task : implement pyMongo repository
Merge branch 'master' into nosql

Conflicts:
	everest/entities/base.py
	everest/querying/base.py
	everest/querying/filtering.py
	everest/querying/ordering.py
	everest/querying/specifications.py
	everest/repositories/memory/aggregate.py
	everest/repositories/memory/querying.py
	everest/repositories/memory/uow.py
	everest/repositories/rdb/querying.py
	everest/representers/base.py
	everest/representers/csv.py
	everest/representers/dataelements.py
	everest/representers/mapping.py
	everest/representers/traversal.py
	everest/resources/attributes.py
	everest/resources/base.py
	everest/resources/descriptors.py
	everest/resources/io.py
	everest/tests/test_aggregates.py
	everest/tests/test_descriptors.py
	everest/tests/test_io.py
	everest/tests/test_representers.py
	everest/tests/test_resources.py
	everest/tests/test_staging_collection.py
	everest/tests/test_uow.py
	everest/tests/test_url.py
	everest/url.py
	everest/utils.py
	everest/views/postcollection.py
Next iteration.
Merge branch 'master' into nosql

Conflicts:
	everest/repositories/memory/querying.py
	everest/repositories/rdb/querying.py
	everest/repositories/rdb/utils.py
	everest/tests/test_aggregates.py
	everest/tests/test_visitors.py
Next iteration.
Merge branch 'master' into nosql

Conflicts:
	everest/entities/base.py
	everest/querying/specifications.py
	everest/repositories/memory/querying.py
	everest/repositories/rdb/querying.py
Next iteration.
Merge branch 'master' into nosql

Conflicts:
	everest/querying/filterparser.py
Next iteration.
Next iteration.
Merge branch 'master' into nosql
Next iteration
Merge branch 'master' into nosql

Conflicts:
	everest/representers/base.py
Next iteration.
First nearly working version of the new PATCH support infrastructure.
Moving the semantics of detecting which attributes to ignore during
resource <-> representation mapping to the Mapping class.
Unit test fixes.
Removing the ill-conceived READ mapping direction functionality (also
reinstates the old IGNORE_OPTION and does away with IGNORE_ON_READ and
IGNORE_ON_WRITE).
Integrated the new traversal proxy infrastructure with the component
architecture.