Emit comments in the .js and .d.ts files

This enables adding comments to the .js and .d.ts for all the declarations when --removeComments is not specified
Note the comments aren't correctly formatted and have extra spacing when they are multiline comment. That is a todo I am fixing separately.
Also handling of copyright comments will be separate pull request
No it does not because writeLine will take care of not emitting unwanted blank statement because of writeLine implementation (which just sets the flag iof new line but does not actually write the new line in the output)