[FIX] demo_cn_console causes segmentation fault

This change fixes a missing pointer initialization in the change
[FIX] Fix resending of the same Tx buffer in BasicEthernet state
which causes a segmentation fault.

Change-Id: I7454657bc5b4b470a8834539f772b4bc5e9f2cac
[FIX] Fix wrong data type in comparison

Change-Id: Idfe3d9bbf84afeb4d53d62a9583610ce264f820d
[FIX] Prevent API to call stack functions if stack is not ready

The API modules call internal stack functions. If the stack is not
initialized this may cause unexpected behaviour. Now, each API call
checks if stack is initialized before calling a stack internal function.

Change-Id: I5afc08cdabfb5d0e24c3ff5a10055d08540c2391
[FIX] Correctly stop synchronous data thread in console demo apps

If the console demos are using a separate thread for PDO data exchange,
this thread must be stopped before the stack is shutdown to prevent
memory errors.

Change-Id: I8c07c9a372babe05ec7c8a7a47911c42cae157dc
[FIX] Correctly stop synchronous data thread in demo_mn_qt

If the QT demo is using a separate thread for PDO data exchange,
this thread must be stopped before the stack is shutdown to prevent
memory errors.

Change-Id: I16b4097fa8048ecf63e4218da236c76c76b0efac
[FIX] Add missing CMake option for sync thread in demo_cn_console

Change-Id: I3b771ff47d6a52c1475581e3807e9669b4705756
[TASK] Update release information

- Updating version numbers
- Add release notes

Change-Id: I6f1e0d59cfa238b9b5c5b0589edfdbc70b090429