C104

- Add support for Qualifier of Command for single, double and regulating step commands
- Fix transmit updated_at timestamp for time aware point
- c104.Point.set method signature improved (non-breaking):
- Add keyword argument timestamp_ms to allow setting a points value in combination with an updated_at_ms timestamp
- Improve value argument to support instances of type c104.Double and c104.Step as setter for c104.Point.value does
- Improve GIL handling for methods station.add_point, server.stop and client.stop

- Fix (1.17.1): Fix select-and-execute for C_SE_NA
- Fix (1.17.1): Fix armv7 build

- Add optional feature **Select-And-Execute** (also called Select-Before-Execute)
- Add enum c104.CommandMode
- Add properties point.command_mode, point.selected_by and incomingmessage.is_select_command
- on_receive callback argument previous_state contains key selected_by
- Add select field to explain_bytes and explain_bytes_dict

- Fix free command response state key if command was never send
- Improve point transmission handling
- Improve documentation

- Add feature TLS (working versions: SSLv3.0, TLSv1.0, TLSv1.1, TLSv1.2; not working: TLSv1.3)

- Fix potential segmentation fault by using smart pointer with synchronized reference counter between cpp and python

- Improve CMake structure

- Improve reconnect behaviour

- Update lib60870-C to latest

- Fix (1.15.2): Fix deadlock between GIL and client-internal mutex.

- Add new Connection callback __on_state_change__ (connection: c104.Connection, state: c104.ConnectionState) -> None

- Add new enum c104.ConnectionState (OPEN, CLOSED, ...)

- Allow COT 7,9,10 for command point transmit() from server side to support manual/lazy command responses

- Add new enum c104.ResponseState (FAILURE, SUCCESS, NONE)

- __BC signature of callback server.on_clock_sync changed__
- Return c104.ResponseState instead of bool

- __BC signature of callback point.on_receive changed__
- Return c104.ResponseState instead of bool

- Fix (1.14.2): Fix potential segmentation fault

- Fix (1.14.1): Add missing option c104.Init.NONE

- Add c104.Init enum to configure outgoing commands after START_DT, defaults to c104.Init.ALL which is equal to previous behaviour

- Clients timeout_ms parameter is used to configure maximum rtt for message in lib60870-C \
(APCI Parameter t1: max(1, (int)round(timeout_ms/1000)))

- __BC callback signature validation__
- Allow functools.partial, functools.partialmethod and extra arguments in callbacks that have a default/bound value
- Ignore arguments with non-empty default value n callback signature validation

- Fix (1.13.6): try send clock sync only once after start_dt

- Fix (1.13.5): Silence debug output, update dependencies

- Fix (1.13.4): PointCommand encode REGULATION STEP COMMAND values, windows stack manipulation in server

- Fix (1.13.3): IncomingMessage decode DOUBLE POINT values 0.0, 1.0, 2.0, 3.0

- Fix (1.13.3): IncomingMessage allows 0.0,1.0,2.0,3.0 values for DoubleCommands, message.value returns value instead of IOA

- Fix (1.13.2): Server sends multiple ASDU per TypeID in InterrogationResponse or Periodic transmission if IOs exceed single ASDU size

- __BC for on_clock_sync__ \
Callable must return a bool to provide act-con feedback to client
- __Respond to global CA messages__ \
Fix: Server confirms messages that are addressed at global ca from each local CA with its own address.