arduino/Arduino#4673

Signed-off-by: Frederic.Pillon <frederic.pillon@st.com>

When iterating we make sure client's socket is not closing
since _tcp_client remains after close.

This was tested on nuleo-f767zi using project webthing-arduino

Change-Id: Ie465fe59009c33957dad97f1c70b4dc3af3b2ebe
Forwarded: #17
Signed-off-by: Philippe Coval <p.coval@samsung.com>

Also replace default constructor to use port 80 by default.

I noticed that server worked on global instance.
but not if used in class (allocated with new).

This change makes both use cases working.

Forwarded: #17
Relate-to: https://github.com/rzr/webthing-iotjs/wiki/MCU
Change-Id: I2e21e34a43f3cadb7981f2e359a5960735daa5d3
Signed-off-by: Philippe Coval <p.coval@samsung.com>

client: Fix bool operator on init and ongoing use

variant.h is now included thanks stm32_def.h

See stm32duino/Arduino_Core_STM32#518

Signed-off-by: Frederic.Pillon <frederic.pillon@st.com>

depending of the STM32 Core Version

Signed-off-by: Frederic.Pillon <frederic.pillon@st.com>

by adding a 'lwipopts_extra.h'


Signed-off-by: Frederic.Pillon <frederic.pillon@st.com>

SSLClient needs these functions

This patch allows the WebClientRepeating example to work.

Also remove 2 printf debug.

Signed-off-by: Frederic Pillon <frederic.pillon@st.com>

UDP connected sockets are limited to commuinicating with one
host and port.

Implemented begin multicast for receiving multicast udp.
Added ability to add a callback from the interrupt when udp
receive data (Usefull with FreeRTOS).
```
void EthernetUDP::onDataArrival( std::function<void()> onDataArrival_fn){
  _udp.onDataArrival = onDataArrival_fn;
}
```

Signed-off-by: Frederic Pillon <frederic.pillon@st.com>