Report error if exports or require is used for declaration name in external module

Fixes #63
Negative test cases for collision of export and require declaration names
Merge pull request #569 from Microsoft/collisions

Report error if exports or require is used for declaration name in external module
Use double quotes in declaration file's reference path generation so that quotes in file name wouldnt affect reference resolution

Fixes #474
Merge pull request #605 from Microsoft/quotesInDeclarationFile

Use double quotes in declaration file's reference path generation
Merge branch 'master' into emitDeclarationWithNoResolve