Test - Integrate - Control

TOPE Upgrade to Tcl 8.6

The Tcl core in TOPE will soon be updated to version 8.6

We are planning to update the Tcl version used in TOPE from the current 8.4 to 8.6

The benefits are expected to be (highlights):
- the TOPE debugger is replaced with a new Terma-developed one
- support for IPv6
- native support for large integers
- new language constructs like dict, coroutines and improved introspection

The impacts will be:
- it appears unlikely that we can continue the maintenance of the BLT plugin (known maintenance problem)

We would not recommend to start new projects heavily relying on the BLT plugin.

The migration will be managed as follows:
- a final stable tested release based on 8.4 will be published for all platforms
- the daily build will be switched to 8.6
- Terma will test and use day-to-day for a period
- a formal tested release based on 8.6 will be published

Despite best efforts, we cannot absolutely exclude the possibility of regressions, in this event customers may be recommended to revert to the last tested 8.4 release, which of course will be kept available.