Fixes default for project specific compiler settings

Don't reset to default values when disabling project specific compiler settings.
Adds support for boolean settings with default values in the compiler settings hierarchy.

Fixes #1002083
replaces CheckBoxSettingWithDefault with a by-name parameter and additional constructor

Thanks @skyluc for the simplification.
Merge pull request #681 from huitseeker/pr/674

Fixes default for project specific compiler settings