Enhancement: Allow older devices to use enbloc dialing (for example 7936)

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5587 43c1dc8c-776e-4df2-8ef1-6e829299be21
Enhancement: use device connected for CONNECTED CONFERENCE indication

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5588 43c1dc8c-776e-4df2-8ef1-6e829299be21
Fix: selectedchannel should not use retain/release (Reported by Antonio)

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5589 43c1dc8c-776e-4df2-8ef1-6e829299be21
Enhancement: For hint + non shared line get the last channel, instead of the first. The last one is most likely the most recent

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5590 43c1dc8c-776e-4df2-8ef1-6e829299be21