refactored CachingTaskTest
added TaskTest
merged AbstractNode into Node
added NodeTest
added TaskContainerCreator
reused TaskContainerCreator in TaskGenerator, added TaskGeneratorTest
redesigned ScriptParserTest
name cleanup in SandboxImpl
changed formatting of output printed by UserConsole
refactored NativeCallHasher
renamed NativeCallHasher -> CallHasher and moved from .task.base package to .function.base package
added CachableFunction
reused CachableFunction
fixed ImportedFunctionsProvider so file/files function are not cachable