Class: ParseDirective
ParseDirective
ParseDirective handles a `$parse` directive.
The work of this directive is limited to scaning for and calling other directives.
Directives found are handled in this order:
1. $resource
2. $set
3. $request
4. $parse | $compile
A `$parse directive must have a $parse or a $compile but not both!
In the case of an embedded $parse, this $parse SHOULD have a `$compile` or
some `$parse` that has a `$compile` in its ancestors.
In other words, the work of a compiler MUST end with a $compile.