* Add tls_client example
This requires pico_mbedtls in the pico-sdk
Connects to worldtimeapi.org and retrieves a web page
Originally written by Floris Bos @maxnet
* Add dns server
The access point example is a bit complicated to use as you have to open
a browser and enter a url with the IP address of the device
Add a simple dns server that can be used to make the access point behave
like a captive portal. All DNS requests point back to the gateway IP.
* Improve AP example
The web page /ledtest gives you a web page with an option to turn the
led on and off
Start the DNS server and redirect all HTTP requests to this page.
Improve the code so it can handle more than one request at a time.
Fixes: #232
Now LWIP_PLATFORM_ASSERT has been fixed we're seeing an assert for the
ping example app.
It sets the SO_RCVTIMEO socket option which is not enabled.
Fixes#308
