Add 'scIsConnected()' method to API to make application connection waiting more flexible.

[jekyll2014]

Making my C# app I found it more comfortable to use the flag instead of the stopper method.

[tshino]

Hi! @jekyll2014 ,
Thank you very much!
I agree this was a missing feature and must be useful for certain situations.

[tshino]

It seems you forgot to commit another changed file SenderAPI.h.
Would you please add the file? Then I can merge this PR.

[jekyll2014]

Domo origato!

Hi! @jekyll2014 , Thank you very much! I agree this was a missing feature and must be useful for certain situations.

I'll also try to check if it's possible to detect the application disconnected event... This will be very useful too.
And as far as I can understand the camera name could be set from the caller...

It seems you forgot to commit another changed file SenderAPI.h. Would you please add the file? Then I can merge this PR.

My bad. Sorry, that's my first commit on GitHub (never tried it for the past 10 years). Will fix it surely.