Added tests.
Refactoring emitDeclaration, separate emitDeclaration from emitFiles
Refactoring parameters formatting
Update language service to use getDeclarationDiagnostics instead of emitFile to get declaration errors
Add test case to make sure that we only report an error from target file
Address code review
Fix signature help crash when requested outside argument list
Comment examples of when findListItemInfo can return undefined
Merge pull request #890 from Microsoft/sigHelpCrash

Fix signature help crash when requested outside argument list
Addres code review
Merge remote-tracking branch 'origin/release-1.3' into reportErrorFromTargetFile
Merge branch 'reportErrorFromTargetFile' into release-1.3
use getCanonicalFileName in the language service when searching for files
Merge pull request #925 from Microsoft/cannotFindFileFix

use getCanonicalFileName in the language service when searching for files
Update LKG
Fix the crash in declaration file emit when alias is used before its declaration

Fixes #938
Added another test case (#948)
Merge pull request #940 from Microsoft/asynchrounousAliasWriteCrash

Fix the crash in declaration file emit when alias is used before its declaration
Update LKG
Expose getSourceFile on the LanguageService interface