launch files for maps -- using 'initial_goal' parameter to select which OWL file is to be loaded
renamed parameter from 'goal' to 'initial_goal' in JSONPrologNode
semantic map tools Prolog init files
removed .gradle folders again -- they are definitely auto-generated and should not be in the repo
updated package reference from ias_knowledge_base to knowrob_common in semantic map OWL files
added .gradle folders to default gitignore