Add CompileResultWithTemplate function

Hello,

I added `CompileResultWithTemplate` function to Ace to receive `*template.Template` value which is created somewhere as its argument and append compiled template to the value. Of course, we can append the compiled template to others by using `AddParsedTree` but it doesn't allow us to use `FuncMap` defined in others because `*template.Template` doesn't have a function returns `FuncMap`. In this implementation, `FuncMap` defined in passed `*template.Templates` value is merged with Ace own builtin FuncMap and can be called in templates.