C# bindings: Allow to create context from URI
C# bindings: Allow to create context from URI

The IIO context can be created by instanciating a Context object, using
the URI as argument:

ctx = Context("ip:127.0.0.1")

For compatibility with existing code, it is still possible to create the
IIO context by passing the IP or hostname directly to the constructor.

Signed-off-by: Paul Cercueil <73d292422978d45c9eeef455bb1b24a0db453722@analog.com>

analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio