removes reversion
add versioning model
add task for model versioning
add versioning to resource + fixes to versioning model
fix versioning for resources
add versioning for community
add versioning to organizations
versionng for need
projects versioning
Merge branch 'master' into model_versioning

Conflicts:
	mootiro_maps/apps/community/views.py
	mootiro_maps/apps/investment/models.py
	mootiro_maps/apps/komoo_resource/views.py
	mootiro_maps/apps/need/views.py
	mootiro_maps/apps/organization/views.py
	mootiro_maps/lib/reversion/middleware.py
	mootiro_maps/settings/common.py
	mootiro_maps/templates/default/need/edit_ajax.html
add migration script to model_versioning
Merge pull request #145 from it3s/model_versioning

Model versioning