Documentation of main module is done. Changed methods build_apu to build_adu in Device::Modbus::RTU and TCP and changed tests and their calling code accordingly. Removed diagnostic messages from tests and turned them into simple notes to avoid polluting prove messages.
Removed unnecessary test from Device::Modbus parse_request
Modified RTU method build_adu to receive the request object, which already contains the unit number. Modified the tests that go with it and invoking functions.
Added documentation for Device::Modbus::Client
Moved unit id from transactions to requests/responses in Modbus TCP
POD improvements and Device::Modbus::Spy tests
Removed some conditions that were never exercised from Modbus::Spy