ProjectProvider.GetProjectCheckerOptions sets ProjectOptions.ReferencedProjects and alters ProjectOptions.ProjectOptions
fixed: wrong value was assigned to ProjectOptions.ReferencedProjects

check ProjectOptions.ProjectOptions and ProjectOptions.ReferencedProjects consistency
refactor ProjectProvider.GetProjectCheckerOptions
Merge pull request #410 from vasily-kirichenko/set-ReferencedProjects-in-project-options

ProjectProvider.GetProjectCheckerOptions sets ProjectOptions.ReferencedProjects and alters ProjectOptions.ProjectOptions