test_zgossip: assert constructors
zactor: Fix memory leak when shim can't be allocated
zauth: Check errors in constructor
zauth: Add FIXME for unchecked constructor
zauth: Check errors in zap_request constructor
zauth: Check constructor for new zauth
zauth: Check errors in test
zauth_v2: handle errors in constructor better
zauth_v2: handle errors in zap_request constructor
zauth_v2: handle errors in agent constructor
zauth_v2: handle errors in agent
zauth_v2: check constructors in test
zbeacon: Check allocations in constructor
zbeacon: Assert constructors
zbeacon: Assert constructors in test
zbeacon_v2: Handle errors in constructor better
zbeacon_v2: assert constructors
zbeacon_v2: Handle error in agent constructor better
zbeacon_v2: Assert constructors in test
zcert: remove code duplication