Properly set exit code for process.
Supercedes #246.
Includes provisions for buggy behavior of WScript.Quit.
Merge pull request #249 from Microsoft/setProcessExitCode

Properly set exit code for process.
Fix up comment about bug #236 in checkCallExpression
Merge pull request #257 from Microsoft/untyped

Fix up comment about in checkCallExpression
Merge branch 'master' into forInError