Improve syntax error message with Hints #165

Here is an example where I used a syntax from LiquidHaskell in LiquidJava.
It would be helpful to have more info using an example.
We could like: If we knew that the syntax error was inside an alias, to provide an example of how we usually write aliases, like "Common example is: @RefinementAlias("Percentage(int v) { 0 <= v && v <= 100 }")"

Here is the example that I'm referring to: