html/install.js (InstallView): import schema validator and run it against downloaded mapping and resource definitions
html/repo_query.js (RepoEntry): import schema validator and run it against obtained query results
test/haketilo_test/unit/test_install.py (test_install_normal_usage, test_install_dialogs): use underscore instead of hyphen in item identifiers
test/haketilo_test/unit/test_install.py (test_install_dialogs): adapt error message test cases to new handling method of invalid JSON instanced
test/haketilo_test/unit/test_repo_query.py (test_repo_query_normal_usage): use underscore instead of hyphen in item identifiers
test/haketilo_test/unit/test_repo_query.py (test_repo_query_messages): use higher sample unsupported schema version to avoid having to modify the test case soon
test/haketilo_test/world_wide_library.py: use underscore instead of hyphen in item identifiers
common/jsonschema.js, common/jsonschema: adapt tdegrunt's jsonschema and include in Haketilo, load schema documents from schemas/
validate repository responses against JSON schemas