input/logictree: less confusing messages for parse and validation errors
input/logictree: less confusing messages for parse and validation errors


Former-commit-id: d95d9ad6605b48b4f1e99805dbea04b8a37dc8f2 [formerly 990cc02db6f0aa72a3a5d236a054bc4893f95a46]
Former-commit-id: b71de96266638d76f98bd3a2ddf00025a163e43f
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine