Make the symbol writing api on the text writer
Checker and emitter changes to report errors on inaccessibility of symbols when writing types in declaration file
Report error on Class/Interface heritage clause if it cant be accessed
Fixes #78 and #83
Report errors if the type parameter uses constraint that is using private type/module
Fixes #86
Fix the incorrect error reporting and declaration file emit for the type parameter constraint of private methods
Also incorporates code review feedback
Added more comments and todos as per code review feedback
Merge pull request #161 from Microsoft/privacyErrors

Report errors for usage of private types when generating declaration file