Speed up config compiler.

Fixes #5255
Fix leak in the config parser.

Refs #4946
Implement support for making script variables constant.

Refs #4946
Remove Windows example config.

Refs #4946
Implement support for constants in the config parser.

Refs #4946
Fix: display_name property doesn't work for hosts.

Fixes #5258
Merge branch 'feature/constants-4946' into next

Fixes #4946
Add configuration aware test runner

refs #5223