Merge pull request #138 from BnLG/yealink

Yealink enhancements

Hello,
This PR brings several improvements to the Yealink plugin :

It properly adjusts account details display, with its name at the top of the screen, and its number in front of the DSS key.
It enlarges DSS key label zones, so that we can display larger labels.
It brings a bigger DND logo, so that we easily know DND has been left on.
It enables SRTP, if transport is TLS.

Thank you 👍
Before :

After :

Reviewed-by: Alexandre Fournier <None>