v1.0.0-beta.4

Fixed: Child processes generate empty parameters for parameters made available by parents Open-EO/openeo-web-editor#107
Fixed: Improved validation of arrays and objects #2
Fixed: Better error when callback parameter holds no valid process #4
Fixed: Support properties in load_collections #5
Fixed: Improved validation for process graphs and WKT2
Fixed: ProcessGraphNode.getRawArgument() now really returns original / raw argument value
Added: ProcessGraphNode.getParsedArgument() returns now what ProcessGraphNode.getRawArgument() has returned before
Added: Utils.containsRefs()
Added: ProcessGraphNode.getDescription()
Added: JsonSchemaValidator.setProcessGraphParser()
Removed: Moved JsonSchemaValidator.convertSchemaToArray() to ProcessUtils.normalizeJsonSchema()
Removed: ProcessgraphNode.getRawArgumentValue() - use Utils.getType() and ProcessgraphNode.getRawArgument() instead
Changed: ProcessgraphNode.getType() is now Utils.getType()
Changed: ProcessgraphNode.getValueRefs() is now Utils.getRefs()
Changed: Previous / Next nodes in process graph nodes are now unique
Changed: ProcessgraphNode.getPreviousNodes() / ProcessgraphNode.getNextNodes() are now returned sorted by id
Changed: ProcessgraphNode.getProcessGraphParameter() is now ProcessgraphNode.getProcessGraphParameterValue()
Chore: Code refactoring, more tests, improved documentation