[doc] 6.22.1 highlights

Merge pull request Ericsson#3883 from vodorok/workspace_before_loggin…

…g_server

Create workspace directory before logging server

[version] Bump up to version 6.22.0-rc1

Merge pull request Ericsson#3791 from bruntib/fix_fixit_test

[test] Fix fixit test

[version] Bump up to version 6.21.0-rc1

Merge pull request Ericsson#3742 from vodorok/docs

[doc] Extend Cppcheck documentation

[version] Bump up to version 6.21.0-rc1

[bugfix] Determine stats capability in pre-analysis

get_analyzer_checkers() should be used for querying checker list because
this can be used for getting modeling checkers too. Pre-analysis depends
on the existence of some modeling checkers.

Merge pull request Ericsson#3620 from csordasmarton/new_features_6.19.0

[gui] Describe new features in 6.19.0

[version] Bump up version to 6.18.2