Add additional integration test proving bug #1302 highest severity.

Add integration test demonstrating that the bug reported in GitHub
issue #1302 can cause TLC to miss property violations, confirming
that the bug leads to incomplete verification results.

Part of Github issue #1302
#1302

[Tests][TLC]

Signed-off-by: Markus Alexander Kuppe <[email protected]>

Update the Toolbox's update location from lamport.org to dl.tlapl.us.

The domain tlapl.us will be owned and managed long-term by the TLA+ Foundation.

[Toolbox]

Signed-off-by: Markus Alexander Kuppe <[email protected]>

LazyValue can cause TLC to generate too many or too few states.

Remove @OverRide to compile with older test framework.

Part of Github issue #798
#798

[Bug][TLC][Changelog]

Signed-off-by: Markus Alexander Kuppe <[email protected]>

3c7caa5

Thread safety concerns due to "memory barrier" pattern in value classes.

Logical backport of Github issue #439
#439

[Bug][TLC]

Bump version numbers of master to 1.8.0 in anticipation of a 1.7.1

maintenance release from a 1.7.1 branch.

[Build]

Bump version numbers of master to 1.8.0 in anticipation of a 1.7.1

maintenance release from a 1.7.1 branch.

[Build]

Remove pack200 compression from CloudTLC because it has

been deprecated in Java 11 and finally deleted from
Java 14.

Related to Github issue #442
#442

[Bug][Toolbox]

Update to JDK 14.0.1

Closes Github issue #442
#442

[Feature][Toolbox]

1.6.0 release